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1.
Clin Dysmorphol ; 33(3): 137-144, 2024 Jul 01.
Article in English | MEDLINE | ID: mdl-38410977

ABSTRACT

OBJECTIVE: Fetuses with abnormal karyotypes often exhibit distinctive ultrasonographic markers, including major anomalies and "soft" markers, indicating potential chromosomal issues. A crucial consideration arises when a single fetal anomaly is detected, raising the question of whether karyotyping is warranted, given the associated procedural risks. Our objective was to establish correlations between single fetal anomalies identified through ultrasound and chromosomal abnormalities. METHODS: A cross-sectional study analyzed the karyotype of 1493 fetuses and detected a single ultrasonographic anomaly over a 16-year period. Karyotyping was performed using the standard karyotype technique. Moreover, data regarding the type of anomaly detected ultrasonographically, karyotype results, and outcomes following interventions were collected. Among other methods, the use of positive likelihood ratios (LR+) was used to evaluate the diagnostic accuracy of ultrasound compared to karyotyping. RESULTS: In total, an aberrant karyotype was identified in 99 fetuses (6.6%). This was most commonly observed in cases involving a "soft" marker, occurring in 27 out of 218 fetuses (12.4%). The most frequently detected aberrant karyotype resulted from aneuploidies (80.6% of cases), notably trisomy 21 (50.5%). "Soft" markers predicted chromosomal issues (LR+ = 1.9; OR = 2.4), and isolated polyhydramnios (LR+ = 1.54; OR = 1.6) showed significance in predicting fetal chromosomal aberrations. CONCLUSION: When assessing the necessity for karyotyping in fetuses with single major anomalies or "soft" markers, it is crucial to consider individual risks for chromosomopathies, including the LR+ of the detected marker. In cases where fetuses exhibit isolated anomalies with a normal karyotype, additional diagnostic measures, such as molecular cytogenetic and molecular genetics techniques, may become necessary.


Subject(s)
Abnormal Karyotype , Fetus , Karyotyping , Ultrasonography, Prenatal , Humans , Female , Pregnancy , Ultrasonography, Prenatal/methods , Karyotyping/methods , Cross-Sectional Studies , Fetus/abnormalities , Fetus/diagnostic imaging , Adult , Chromosome Aberrations
2.
Chem Biodivers ; 19(10): e202200578, 2022 Oct.
Article in English | MEDLINE | ID: mdl-36006860

ABSTRACT

Essential oils obtained from different parts of Achillea coarctata species (inflorescences, stem and leaves and the whole aerial part) collected on four different locations in Serbia have been investigated to evaluate the chemical composition and antibacterial activity of isolated oils. The aim of this study was to determine differences in the chemical composition of essential oils obtained from different plant parts and how different type of substrate as well as different climate conditions affect the chemical composition of essential oils. Oxigenated terpenes were reported to be the major constituents in almost all examinated samples with 1,8-cineole, caryophyllene oxide and cis-cadin-4-en-7-ol identified as dominant compounds. Disk diffusion assay was used to determine antibacterial activity against two Gram-positive (Bacillus subtilis subsp. spizizenii ATCC 6633 and Staphylococcus aureus ATCC 6538) and three Gram-negative bacteria (Escherichia coli ATCC 8739, Pseudomonas aeruginosa ATCC 9027 and Salmonella abony ATCC 6017). The obtained results showed that essential oils obtained from A. coarctata exhibit significant antibacterial activity against tested bacteria strains. The best inhibitory effect was observed against S. aureus, while on the other hand P. aeruginosa showed high level of resistance to almost all examined essential oils.


Subject(s)
Achillea , Anti-Bacterial Agents , Oils, Volatile , Staphylococcus aureus , Achillea/chemistry , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/isolation & purification , Anti-Bacterial Agents/pharmacology , Eucalyptol , Gas Chromatography-Mass Spectrometry , Microbial Sensitivity Tests , Oils, Volatile/chemistry , Phytochemicals , Plant Oils/chemistry , Staphylococcus aureus/drug effects , Sesquiterpenes/chemistry , Sesquiterpenes/isolation & purification , Sesquiterpenes/pharmacology
3.
Reprod Sci ; 28(12): 3529-3539, 2021 12.
Article in English | MEDLINE | ID: mdl-34046868

ABSTRACT

The aim of the present study was to analyze the distribution of genotypes and haplotypes of functional eNOS gene polymorphisms in the promoter (-786 T/C), intron 4 (VNTR4b/a) and exon 7 (894 G/T), in Serbian population of pregnant women, and establish a possible association between these polymorphisms and preeclampsia development. DNA was isolated from venous blood samples of 50 heathy pregnant women and 50 preeclampsia patients. Polymerase Chain Reaction/Restriction Fragment Length Polymorphism (PCR/RFLP) technique, with appropriate sets of primers and specific restriction enzymes, was used to determine polymorphisms in eNOS gene. Statistical analysis was done using the SPSS and HAPLOVIEW software packages. eNOS -786 T/C polymorphism was significantly associated with preeclampsia (P = 0.006). Homozygotes for the VNTR polymorphism had also an elevated risk of developing preeclampsia (OR=7.68, 95%CI (0.89-65.98)), especially the mild (OR=9.33, 95%CI (0.98-88.57)) and late form (OR=8.52, 95%CI (0.90-80.58)). The 894 G/T polymorphism was not associated with preeclampsia. "G-C-b" and "T-4a-T" haplotypes were more frequent in preeclampsia, though without reaching statistical significance. -786 T/C and VNTR 4b/a eNOS gene polymorphisms were associated with preeclampsia risk in Serbian patients.


Subject(s)
Genetic Association Studies/methods , Genetic Predisposition to Disease/genetics , Minisatellite Repeats/genetics , Nitric Oxide Synthase Type III/genetics , Polymorphism, Single Nucleotide/genetics , Pre-Eclampsia/genetics , Adult , Female , Genetic Predisposition to Disease/epidemiology , Humans , Linkage Disequilibrium/genetics , Pre-Eclampsia/diagnosis , Pre-Eclampsia/epidemiology , Pregnancy , Serbia/epidemiology
4.
Nat Prod Res ; 34(13): 1947-1950, 2020 Jul.
Article in English | MEDLINE | ID: mdl-30689406

ABSTRACT

Chemical composition of the headspace volatiles and essential oils isolated from different parts of Ferulago sylvatica was determined by GC and GC/MS analyses. The results showed that headspace volatiles obtained from the aerial parts and roots were similar regarding the number of identified compounds and main components. However, essential oils obtained from different plant organs showed significant differences in chemical composition. Myrcene was the most abundant component of the inflorescences and shoots volatiles, while α-pinene make up over 50% of the root volatiles. Only three components were identified in the root essential oil with 2,3,6-trimethyl benzaldehyde (92.7%) as the main component. In the shoots sample the terpenoid fractions represented 56% of the oil, unevenly distributed between monoterpenoids and sesquiterpenoids with germacrene D (32.5%) recognized as the main constituent. On the other hand, more than 94% of the inflorescences oils were monoterpenoids with myrcene as the most abundant contributor (29.2%).


Subject(s)
Apiaceae/chemistry , Oils, Volatile/chemistry , Plant Extracts/chemistry , Plant Structures/chemistry , Terpenes/analysis , Acyclic Monoterpenes/analysis , Alkenes/analysis , Bicyclic Monoterpenes/analysis , Gas Chromatography-Mass Spectrometry , Monoterpenes/analysis , Plant Oils/chemistry , Serbia , Sesquiterpenes/analysis
5.
Chem Biodivers ; 14(5)2017 May.
Article in English | MEDLINE | ID: mdl-28273389

ABSTRACT

The present study reports the chemical composition of the headspace volatiles (HS) and essential oils obtained from fresh Chaerophyllum aromaticum root and aerial parts in full vegetative phase, as well as biological activities of their essential oils and MeOH extracts. In HS samples, the most dominant components were monoterpene hydrocarbons. On the other hand, the essential oils consisted mainly of sesquiterpenoids, representing 73.4% of the root and 63.4% of the aerial parts essential oil. The results of antibacterial assay showed that the aerial parts essential oil and MeOH extract have no antibacterial activity, while the root essential oil and extract showed some activity. Both of the tested essential oils exhibited anticholinesterase activity (47.65% and 50.88%, respectively); MeOH extract of the root showed only 8.40% inhibition, while aerial part extract acted as an activator of cholinesterase. Regarding the antioxidant activity, extracts were found to be more effective than the essential oils.


Subject(s)
Apiaceae/chemistry , Oils, Volatile/chemistry , Plant Extracts/chemistry , Anti-Infective Agents , Antioxidants/isolation & purification , Antioxidants/pharmacology , Cholinesterase Inhibitors/isolation & purification , Cholinesterase Inhibitors/pharmacology , Monoterpenes/isolation & purification , Sesquiterpenes/isolation & purification
6.
Mol Cell Endocrinol ; 440: 116-124, 2017 01 15.
Article in English | MEDLINE | ID: mdl-27845161

ABSTRACT

Autophagy, a process of controlled cellular self-digestion, could be involved in cyclic remodeling of the human endometrium. We investigated endometrial mRNA expression of 23 autophagy-related (ATG) genes and transcription factors in healthy controls (n = 12) and anovulatory polycystic ovary syndrome (PCOS) patients (n = 24), as well as in their subgroup (n = 12) before and after metformin treatment. The mRNA levels of transcription factor forkhead box protein O1 (FOXO1) and several molecules involved in autophagosome formation (ATG13, RB1-inducible coiled-coil 1), autophagosome nucleation (ATG14, beclin 1, SH3-domain GRB2-like endophilin B1), autophagosome elongation (ATG3, ATG5, γ-aminobutyric acid receptor-associated protein - GABARAP), and delivery of ubiquitinated proteins to autophagosomes (sequestosome 1), were significantly reduced in anovulatory PCOS compared to healthy endometrium. Free androgen index, but not free estrogen index, insulin levels, or body mass index, negatively correlated with the endometrial expression of ATG3, ATG14, and GABARAP in PCOS patients. Treatment of PCOS patients with metformin (2 g/day for 3 months) significantly increased the endometrial mRNA levels of FOXO1, ATG3, and UV radiation resistance-associated gene. These data suggest that increased androgen availability in PCOS is associated with metformin-sensitive transcriptional downregulation of endometrial autophagy.


Subject(s)
Autophagy/genetics , Down-Regulation/genetics , Endometrium/metabolism , Polycystic Ovary Syndrome/genetics , Adult , Autophagy/drug effects , Case-Control Studies , Down-Regulation/drug effects , Endometrium/drug effects , Endometrium/pathology , Female , Gene Expression Profiling , Humans , Metformin/pharmacology , Metformin/therapeutic use , Polycystic Ovary Syndrome/drug therapy
7.
Nat Prod Commun ; 11(4): 543-5, 2016 Apr.
Article in English | MEDLINE | ID: mdl-27396214

ABSTRACT

This study reports the essential oil composition and headspace volatiles profile of Achillea coarctata Poir. from Serbia. The inflorescences, stems and leaves, and the aerial parts of A. coarctata were analyzed separately. Germacrene D, α-terpineol and 1,8-cineole were the main constituents of the aerial parts essential oil; 1,8-cineole, cis-cadin-4-en-7-ol and α-terpineol were the most dominant compounds in the inflorescence essential oil, while the most abundant components in the stem and leaf oil were germacrene D, cis-cadin-4-en-7-ol and ledol. The percentages of monoterpenoids and sesquiterpenoids in the aerial parts were the same, while there were differences in distribution of these compound classes in inflorescence and stem and leaf essential oils. The major components of the headspace volatiles were the same for aerial parts, inflorescence and stem and leaves: 1,8-cineole, ß-pinene and α-pinene.


Subject(s)
Achillea/chemistry , Oils, Volatile/chemistry , Volatile Organic Compounds/chemistry , Serbia
8.
Nat Prod Commun ; 10(8): 1439-41, 2015 Aug.
Article in English | MEDLINE | ID: mdl-26434137

ABSTRACT

The present study reports the chemical composition on the essential oil obtained from fresh roots, stems, inflorescences and fruits of Chaerophyllum temulum. In all samples, except the roots, the most dominant components were sesquiterpene hydrocarbons. (Z)-Falcarinol was the principal constituent of the root essential oils (61.7% at the flowering stage and 62.3% at the fruiting stage). The blossom oil was dominated by (Z,E)-α-famesene (23.4%), (E)-ß-farnesene (9.0%) and germacrene D-4-ol (9%), whereas the oil from the fruit had germacrene D-4-ol (27.6%) as its main compound, accompanied by (Z,E)-α-famesene (13.4%). Germacrene D was the most abundant component of the stem essential oil (38.4% at the flowering stage and 32.5% at the fruiting stage). The obtained results show that the qualitative composition of the oil depends on the part of the plant which is analyzed, while the quantitative composition of the main components depends on the growing stage of the plant.


Subject(s)
Apiaceae/chemistry , Oils, Volatile/chemistry , Plant Oils/chemistry , Plant Leaves/chemistry , Plant Roots/chemistry , Plant Stems/chemistry
9.
Biochem J ; 468(1): 49-63, 2015 May 15.
Article in English | MEDLINE | ID: mdl-25731850

ABSTRACT

Altered secretion of insulin as well as glucagon has been implicated in the pathogenesis of Type 2 diabetes (T2D), but the mechanisms controlling glucagon secretion from α-cells largely remain unresolved. Therefore, we studied the regulation of glucagon secretion from αTC1-6 (αTC1 clone 6) cells and compared it with insulin release from INS-1 832/13 cells. We found that INS-1 832/13 and αTC1-6 cells respectively secreted insulin and glucagon concentration-dependently in response to glucose. In contrast, tight coupling of glycolytic and mitochondrial metabolism was observed only in INS-1 832/13 cells. Although glycolytic metabolism was similar in the two cell lines, TCA (tricarboxylic acid) cycle metabolism, respiration and ATP levels were less glucose-responsive in αTC1-6 cells. Inhibition of the malate-aspartate shuttle, using phenyl succinate (PhS), abolished glucose-provoked ATP production and hormone secretion from αTC1-6 but not INS-1 832/13 cells. Blocking the malate-aspartate shuttle increased levels of glycerol 3-phosphate only in INS-1 832/13 cells. Accordingly, relative expression of constituents in the glycerol phosphate shuttle compared with malate-aspartate shuttle was lower in αTC1-6 cells. Our data suggest that the glycerol phosphate shuttle augments the malate-aspartate shuttle in INS-1 832/13 but not αTC1-6 cells. These results were confirmed in mouse islets, where PhS abrogated secretion of glucagon but not insulin. Furthermore, expression of the rate-limiting enzyme of the glycerol phosphate shuttle was higher in sorted primary ß- than in α-cells. Thus, suppressed glycerol phosphate shuttle activity in the α-cell may prevent a high rate of glycolysis and consequently glucagon secretion in response to glucose. Accordingly, pyruvate- and lactate-elicited glucagon secretion remains unaffected since their signalling is independent of mitochondrial shuttles.


Subject(s)
Glucagon/metabolism , Insulin/metabolism , Islets of Langerhans/metabolism , Animals , Aspartic Acid/metabolism , Cell Line , Diabetes Mellitus, Type 2/metabolism , Diabetes Mellitus, Type 2/physiopathology , Glucagon-Secreting Cells/drug effects , Glucagon-Secreting Cells/metabolism , Glucose/metabolism , Glucose/pharmacology , Glycerophosphates/metabolism , Glycolysis , In Vitro Techniques , Insulin Secretion , Insulin-Secreting Cells/drug effects , Insulin-Secreting Cells/metabolism , Islets of Langerhans/drug effects , Kinetics , Malates/metabolism , Male , Membrane Transport Proteins/metabolism , Metabolome , Mice , Mice, Inbred C3H , Mice, Transgenic , Mitochondria/metabolism
10.
Hum Mol Genet ; 23(21): 5733-49, 2014 Nov 01.
Article in English | MEDLINE | ID: mdl-24916378

ABSTRACT

We have previously identified transcription factor B1 mitochondrial (TFB1M) as a type 2 diabetes (T2D) risk gene, using human and mouse genetics. To further understand the function of TFB1M and how it is associated with T2D, we created a ß-cell-specific knockout of Tfb1m, which gradually developed diabetes. Prior to the onset of diabetes, ß-Tfb1m(-/-) mice exhibited retarded glucose clearance owing to impaired insulin secretion. ß-Tfb1m(-/-) islets released less insulin in response to fuels, contained less insulin and secretory granules and displayed reduced ß-cell mass. Moreover, mitochondria in Tfb1m-deficient ß-cells were more abundant with disrupted architecture. TFB1M is known to control mitochondrial protein translation by adenine dimethylation of 12S ribosomal RNA (rRNA). Here, we found that the levels of TFB1M and mitochondrial-encoded proteins, mitochondrial 12S rRNA methylation, ATP production and oxygen consumption were reduced in ß-Tfb1m(-/-) islets. Furthermore, the levels of reactive oxygen species (ROS) in response to cellular stress were increased whereas induction of defense mechanisms was attenuated. We also show increased apoptosis and necrosis as well as infiltration of macrophages and CD4(+) cells in the islets. Taken together, our findings demonstrate that Tfb1m-deficiency in ß-cells caused mitochondrial dysfunction and subsequently diabetes owing to combined loss of ß-cell function and mass. These observations reflect pathogenetic processes in human islets: using RNA sequencing, we found that the TFB1M risk variant exhibited a negative gene-dosage effect on islet TFB1M mRNA levels, as well as insulin secretion. Our findings highlight the role of mitochondrial dysfunction in impairments of ß-cell function and mass, the hallmarks of T2D.


Subject(s)
Diabetes Mellitus, Type 2/genetics , Diabetes Mellitus, Type 2/metabolism , Insulin/biosynthesis , Mitochondria/genetics , Mitochondria/metabolism , Transcription Factors/genetics , Animals , Cell Survival/genetics , Disease Models, Animal , Female , Gene Expression , Humans , Inflammation/genetics , Inflammation/metabolism , Insulin-Secreting Cells/metabolism , Islets of Langerhans/metabolism , Islets of Langerhans/pathology , Male , Mice , Mice, Knockout , Mitochondria/ultrastructure , Oxidative Stress , RNA, Messenger/genetics , RNA, Messenger/metabolism , Reactive Oxygen Species/metabolism , Transcription Factors/deficiency
11.
Endocr Res ; 37(2): 78-88, 2012.
Article in English | MEDLINE | ID: mdl-22489921

ABSTRACT

BACKGROUND: The aim of this study was to prospectively evaluate plasma kisspeptin levels in 129 singleton pregnancies with diabetes [pregestational insulin-dependent diabetes mellitus (type 1) and gestational diabetes (GD)] and hypertensive disease [chronic hypertension (CH), gestational hypertension, and preeclampsia (PE)] as a potential marker of placental dysfunction and adverse perinatal outcome. STUDY DESIGN: Kisspeptin levels were evaluated in the first, second, and third trimesters in patients with type 1 diabetes (16 patients), H (22), and healthy control (25) and in the second and third trimesters in patients with GD (20), gestational hypertension (18), and PE (28). Maternal kisspeptin levels were correlated with pregnancy outcome, parameters of fetoplacental circulation, ultrasound-detected abnormalities of placental morphology, and placental weight at delivery. RESULTS: In pregnancies with type 1 diabetes and H, mean kisspeptin levels were significantly lower compared with the control group (p<0.001 in the first and second trimesters and p<0.05 in the third trimester). Decreased plasma kisspeptin levels in the second and third trimesters were found in patients with GD (p<0.001 in the second and third trimesters) and PE (p<0.001 in the second trimester and p<0.05 in the third trimester). In patients with PE and placental dysfunction, low kisspeptin levels in the third trimester were associated with adverse perinatal outcome. CONCLUSIONS: Our study demonstrates reduced kisspeptin levels in pregnancies with diabetes, H, PE, and placental dysfunction. In patients with PE and placental dysfunction, decreased kisspeptin levels were associated with adverse perinatal outcome. Larger studies are needed to investigate the role of kisspeptin as a potential marker of placental dysfunction and adverse perinatal outcome.


Subject(s)
Diabetes, Gestational/blood , Hypertension/blood , Kisspeptins/blood , Placenta Diseases/blood , Pregnancy Complications, Cardiovascular/blood , Pregnancy in Diabetics/blood , Adult , Female , Humans , Hypertension/complications , Pre-Eclampsia/blood , Pregnancy , Pregnancy Outcome , Pregnancy Trimester, First , Pregnancy Trimester, Second , Pregnancy Trimester, Third
12.
Metabolism ; 61(7): 978-85, 2012 Jul.
Article in English | MEDLINE | ID: mdl-22304835

ABSTRACT

Nearly all mammalian cells express a set of genes known as clock genes. These regulate the circadian rhythm of cellular processes by means of negative and positive autoregulatory feedback loops of transcription and translation. Recent genomewide association studies have demonstrated an association between a polymorphism near the circadian clock gene CRY2 and elevated fasting glucose. To determine whether clock genes could play a pathogenetic role in the disease, we examined messenger RNA (mRNA) expression of core clock genes in human islets from donors with or without type 2 diabetes mellitus. Microarray and quantitative real-time polymerase chain reaction analyses were used to assess expression of the core clock genes CLOCK, BMAL-1, PER1 to 3, and CRY1 and 2 in human islets. Insulin secretion and insulin content in human islets were measured by radioimmunoassay. The mRNA levels of PER2, PER3, and CRY2 were significantly lower in islets from donors with type 2 diabetes mellitus. To investigate the functional relevance of these clock genes, we correlated their expression to insulin content and glycated hemoglobin levels: mRNA levels of PER2 (ρ = 0.33, P = .012), PER3 (ρ = 0.30, P = .023), and CRY2 (ρ = 0.37, P = .0047) correlated positively with insulin content. Of these genes, expression of PER3 and CRY2 correlated negatively with glycated hemoglobin levels (ρ = -0.44, P = .0012; ρ = -0.28, P = .042). Furthermore, in an in vitro model mimicking pathogenetic conditions, the PER3 mRNA level was reduced in human islets exposed to 16.7 mmol/L glucose per 1 mmol/L palmitate for 48 hours (P = .003). Core clock genes are regulated in human islets. The data suggest that perturbations of circadian clock components may contribute to islet pathophysiology in human type 2 diabetes mellitus.


Subject(s)
CLOCK Proteins/genetics , Gene Expression Regulation , Islets of Langerhans/metabolism , Adult , Aged , Body Mass Index , Cryptochromes/analysis , Diabetes Mellitus, Type 2/genetics , Diabetes Mellitus, Type 2/metabolism , Diabetes Mellitus, Type 2/physiopathology , Female , Glycated Hemoglobin/analysis , Humans , Insulin/analysis , Insulin/metabolism , Insulin Secretion , Islets of Langerhans/physiopathology , Male , Middle Aged , Period Circadian Proteins/analysis
13.
Environ Sci Technol ; 43(5): 1367-72, 2009 Mar 01.
Article in English | MEDLINE | ID: mdl-19350905

ABSTRACT

Atmospheric constituents may be deposited to and incorporated into plant leaves, with gases entering via stomata, and gas and particles being sorbed at the surface and in some cases traversing the cuticle, possibly reaching the epidermis. Plants are known to be a sink for atmospheric mercury (Hg), and the current paradigm is that uptake of gaseous elemental Hg occurs by way of the stomata. Four plant species, Rudbeckia hirta, Sorghastrum nutans, Andropogon gerardii, and Populus tremuloides, were exposed to air from different sources and with different Hg and CO2 concentrations in light and dark within a gas exchange chamber at approximately 25% relative humidity. Data showed that Hg concentration and air source had a significant effect (p < 0.001) on leaf-atmosphere Hg flux, with more deposition to the leaf occurring in elevated-Hg air, and in scrubbed air compared to ambient air. Deposition also occurred during dark and elevated CO2 exposures, when stomatal conductance was reduced. These observations and the fact that limited or no Hg emission occurred after deposition of atmospheric Hg suggests that the nonstomatal pathway may be an important route of foliar accumulation of atmospheric Hg.


Subject(s)
Atmosphere/chemistry , Environmental Monitoring , Mercury/metabolism , Plant Stomata/metabolism , Plants/metabolism , Air , Analysis of Variance , Carbon Dioxide/metabolism , Light , Photosynthesis/radiation effects , Plant Stomata/radiation effects , Steam
14.
Sci Total Environ ; 406(1-2): 227-38, 2008 Nov 15.
Article in English | MEDLINE | ID: mdl-18775555

ABSTRACT

This study focused on characterizing air-surface mercury Hg exchange for individual surfaces (soil, litter-covered soil and plant shoots) and ecosystem-level flux associated with tallgrass prairie ecosystems housed inside large mesocosms over three years. The major objectives of this project were to determine if individual surface fluxes could be combined to predict ecosystem-level exchange and if this low-Hg containing ecosystem was a net source or sink for atmospheric Hg. Data collected in the field were used to validate fluxes obtained in the mesocosm setting. Because of the controlled experimental design and ease of access to the mesocosms, data collected allowed for assessment of factors controlling flux and comparison of models developed for soil Hg flux versus environmental conditions at different temporal resolution (hourly, daily and monthly). Evaluation of hourly data showed that relationships between soil Hg flux and environmental conditions changed over time, and that there were interactions between parameters controlling exchange. Data analyses demonstrated that to estimate soil flux over broad temporal scales (e.g. annual flux) coarse-resolution data (monthly averages) are needed. Plant foliage was a sink for atmospheric Hg with uptake influenced by plant functional type and age. Individual system component fluxes (bare soil and plant) could not be directly combined to predict the measured whole system flux (soil, litter and plant). Emissions of Hg from vegetated and litter-covered soil were lower than fluxes from adjacent bare soil and the difference between the two was seasonally dependent and greatest when canopy coverage was greatest. Thus, an index of plant canopy development (canopy greenness) was used to model Hg flux from vegetated soil. Accounting for ecosystem Hg inputs (precipitation, direct plant uptake of atmospheric Hg) and modeled net exchange between litter-and-plant covered soils, the tallgrass prairie was found to be a net annual sink of atmospheric Hg.


Subject(s)
Atmosphere/chemistry , Ecosystem , Environmental Monitoring/methods , Mercury/analysis , Poaceae/metabolism , Air Pollutants/analysis , Air Pollutants/chemistry , Air Pollutants/metabolism , Mercury/chemistry , Mercury/metabolism , Models, Biological , Poaceae/growth & development , Risk Assessment , Soil Pollutants/analysis , Soil Pollutants/chemistry , Soil Pollutants/metabolism , Time Factors
15.
Vojnosanit Pregl ; 63(7): 648-51, 2006 Jul.
Article in Serbian | MEDLINE | ID: mdl-16875425

ABSTRACT

BACKGROUND/AIM: Diabetes mellitus is associated with an increased risk for neonatal morbidity and mortality. One of the most important goals in treating pregnancies complicated with diabetes is keeping glucose level within the normal range, especially in the first trimester. A portable insulin pump for continuous subcutaneous insulin infusion (CSII) represents the best form of therapy for patients with type 1 diabetes mellitus during pregnancy. The aim of our study was to evaluate the effects of therapy with a portable insulin pump for continuous subcutaneous insulin infusion during the first trimester of pregnancy on the quality of glycoregulation and pregnancy outcome in women with type 1 diabetes mellitus. METHODS: A total of 17 newly diagnosed pregnant women with type 1 diabetes mellitus were treated with CSII therapy for three months. The parameters of glycoregulation (hemoglobin A, glycosylated--HbAlc, mean blood glucose value in daily profiles--MBG, daily requirement for insulin--IJ/kg BM), lipid levels, blood preassure and renal function were estimated before and after the therapy. These parameters were correlated with parameters of pregnancy outcome: fetal weight, APGAR score, duration of pregnancy. RESULTS: There was a significant improvement in HbA1c (8.94 +/- 1.62 vs. 6.90 +/- 1.22 %,p < 0.05), MBG (9.23 +/- 2.22 vs. 6.41 +/- 1.72 mmol/l, p < 0.01), and daily requirement for insulin (0.66 +/- 0.22 vs. 0.55 +/- 0.13 IJ/kg BM, p < 0.05) during the CSII therapy. There were significant correlations between fetal weight and HbAlc (r = -0.60, p < 0.05), triglyceride levels (r = -0.63, p < 0.01), and the number of pregnancies (r = -0.62, p < 0.01), as well as between APGAR score and MBG (r = -0.52, p < 0.05) and cholesterol levels (r = -0.65, p < 0,01) before a portable insulin pump was applicated. CONCLUSIONS: There was a significant improvement in the quality of glycoregulation during CSII therapy in the pregnant women with type 1 diabetes mellitus. The quality of glycoregulation in the moment of conception was the important factor for pregnancy outcome.


Subject(s)
Diabetes Mellitus, Type 1/drug therapy , Insulin Infusion Systems , Pregnancy in Diabetics/drug therapy , Blood Glucose/analysis , Diabetes Mellitus, Type 1/blood , Female , Humans , Pregnancy
16.
Sci Total Environ ; 322(1-3): 167-77, 2004 Apr 25.
Article in English | MEDLINE | ID: mdl-15081746

ABSTRACT

In the late 1800s, mills in the Washoe Lake area, Nevada, used elemental mercury to remove gold and silver from the ores of the Comstock deposit. Since that time, mercury contaminated waste has been distributed from Washoe Lake, down Steamboat Creek, and to the Truckee River. The creek has high mercury concentrations in both water and sediments, and continues to be a constant source of mercury to the Truckee River. The objective of this study was to determine concentrations of total and methyl mercury (MeHg) in surface sediments and characterize their spatial distribution in the Steamboat Creek watershed. Total mercury concentrations measured in channel and bank sediments did not decrease downstream, indicating that mercury contamination has been distributed along the creek's length. Total mercury concentrations in sediments (0.01-21.43 microg/g) were one to two orders of magnitude higher than those in pristine systems. At 14 out of 17 sites, MeHg concentrations in streambank sediments were higher than the concentrations in the channel, suggesting that low banks with wet sediments might be important sites of mercury methylation in this system. Both pond/wetland and channel sites exhibited high potential for mercury methylation (6.4-30.0 ng g(-1) day(-1)). Potential methylation rates were positively correlated with sulfate reduction rates, and decreased as a function of reduced sulfur and MeHg concentration in the sediments. Potential demethylation rate appeared not to be influenced by MeHg concentration, sulfur chemistry, DOC, sediment grain size or other parameters, and showed little variation across the sites (3.7-7.4 ng g(-1) day(-1)).

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