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1.
Biochemistry (Mosc) ; 88(11): 1920-1932, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38105209

RESUMO

Progesterone exerts multiple effects in different tissues through nuclear receptors (nPRs) and through membrane receptors (mPRs) of adiponectin and progestin receptor families. The effect of progesterone on the cells through different types of receptors can vary significantly. At the same time, it affects the processes of proliferation and apoptosis in normal and tumor tissues in a dual way, stimulating proliferation and carcinogenesis in some tissues, suppressing them and stimulating cell death in others. In this study, we have shown the presence of high level of mPRß mRNA and protein in the HepG2 cells of human hepatocellular carcinoma. Expression of other membrane and classical nuclear receptors was not detected. It could imply that mPRß has an important function in the HepG2 cells. The main goal of the work was to study functions of this protein and mechanisms of its action in human hepatocellular carcinoma cells. Previously, we have identified selective mPRs ligands, compounds LS-01 and LS-02, which do not interact with nuclear receptors. Their employment allows differentiating the effects of progestins mediated by different types of receptors. Effects of progesterone, LS-01, and LS-02 on proliferation and death of HepG2 cells were studied in this work, as well as activating phosphorylation of two kinases, p38 MAPK and JNK, under the action of three steroids. It was shown that all three progestins after 72 h of incubation with the cells suppressed their viability and stimulated appearance of phosphatidylserine on the outer surface of the membranes, which was detected by binding of annexin V, but they did not affect DNA fragmentation of the cell nuclei. Progesterone significantly reduced expression of the proliferation marker genes and stimulated expression of the p21 protein gene, but had a suppressive effect on the expression of some proapoptotic factor genes. All three steroids activated JNK in these cells, but had no effect on the p38 MAPK activity. The effects of progesterone and selective mPRs ligands in HepG2 cells were the same in terms of suppression of proliferation and stimulation of apoptotic changes in outer membranes, therefore, they were mediated through interaction with mPRß. JNK is a member of the signaling cascade activated in these cells by the studied steroids.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Progesterona/farmacologia , Progesterona/metabolismo , Receptores de Progesterona/genética , Progestinas/farmacologia , Células Hep G2 , Ligantes , Proteínas Quinases p38 Ativadas por Mitógeno
2.
Biochemistry (Mosc) ; 86(11): 1446-1460, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34906046

RESUMO

Progesterone and its synthetic analogues act on cells through different types of receptors, affecting proliferation and apoptosis. These compounds exert their effect through the nuclear receptors and the insufficiently studied membrane progesterone receptors (mPRs) belonging to the progestin and adiponectin Q receptor (PAQR) family. We have identified two selective ligands of mPRs that activate only this type of progesterone receptors - 19-hydroxypregn-4-en-20-one (LS-01) and 19-hydroxy-5ß-pregn-3-en-20-one (LS-02). The goal of this work is to study the effect of these compounds on proliferation and death of human pancreatic adenocarcinoma cells BxPC3 and involvement of the two kinases (p38 MAPK and JNK) in signaling pathways activated by progestins through mPRs. It was shown that progesterone and the compound LS-01 significantly (p < 0.05) inhibited the BxPC3 cell viability, with JNK serving as a mediator. The identified targets of these two steroids are the genes of the proteins Ki67, cyclin D1, PCNA, and p21. Progesterone and the compound LS-01 significantly (p < 0.05) stimulate DNA fragmentation, enhancing the cell death. The p38 mitogen-activated protein kinase (MAPK) is a key mediator of this process. The BCL2A1 protein gene was identified as a target of both steroids. The compound LS-02 significantly (p < 0.05) alters membrane permeability and changes the exposure of phosphatidylserine on the outer membrane leaflet, also enhancing the cell death. This compound acts on these processes by activating both kinases, JNK and p38 MAPK. The compound LS-02 targets the genes encoding the proteins HRK, caspase 9, and DAPK.


Assuntos
Apoptose/efeitos dos fármacos , Citotoxinas/farmacologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Proteínas de Neoplasias/metabolismo , Neoplasias Pancreáticas/metabolismo , Receptores de Progesterona/metabolismo , Linhagem Celular Tumoral , Humanos , Ligantes , Proteínas de Neoplasias/agonistas , Proteínas de Neoplasias/genética , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Receptores de Progesterona/agonistas , Receptores de Progesterona/genética , Neoplasias Pancreáticas
3.
Artigo em Inglês | MEDLINE | ID: mdl-32545855

RESUMO

This article describes a lethal case of leptospirosis that occurred in Southern Russia. The Leptospira strain was isolated and characterized using a microscopic agglutination test, MALDI-TOF mass spectrometry, targeted PCR, and high-throughput sequencing. We show that molecular and mass-spectrometry methods can be an alternative to conventional methods of leptospirosis diagnostics and Leptospira study, which require highly qualified staff and can be performed only at specialized laboratories. We also report the first whole genome of L. interrogans isolated in Russia.


Assuntos
Leptospira interrogans , Leptospira , Leptospirose , Adolescente , Testes de Aglutinação , Humanos , Federação Russa
4.
Acta Crystallogr B Struct Sci Cryst Eng Mater ; 75(Pt 4): 578-590, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32830715

RESUMO

The high-temperature (HT) behaviour of lobanovite, K2Na(Fe2+4Mg2Na)Ti2(Si4O12)2O2(OH)4, was studied using in situ powder X-ray diffraction in the temperature range 25-1000°C and ex situ single-crystal X-ray diffraction of 17 crystals quenched from different temperatures. HT iron oxidation associated with dehydroxylation starts at 450°C, similar to other ferrous-hydroxy-rich heterophyllosilicates such as astrophyllite and bafertisite. A prominent feature of lobanovite HT crystal chemistry is the redistribution of Fe and Mg+Mn cations over the M(2), M(3), M(4) sites of the octahedral (O) layer that accompanies iron oxidation and dehydroxylation. This HT redistribution of cations has not been observed in titanosilicates until now, and seems to be triggered by the need to maintain bond strengths at the apical oxygen atom of the TiO5 pyramid in the heteropolyhedral (H) layer during oxidation-dehydroxylation. Comparison of the HT behaviour of lobanovite with five-coordinated Ti and astrophyllite with six-coordinated Ti shows that the geometry of the Ti polyhedron plays a key role in the HT behaviour of heterophyllosilicates. The thermal expansion, geometrical changes and redistribution of site occupancies which occur in lobanovite under increasing temperature are reported. A brief discussion is given of minerals in which the cation ordering (usually for Fe and Mg) occurs together with iron oxidation-dehydroxylation at elevated temperatures: micas, amphiboles and tourmalines. Now this list is expanded by the inclusion of titanosilicate minerals.

5.
J Acoust Soc Am ; 144(4): EL281, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30404464

RESUMO

A line array of 14 ocean bottom seismographs was deployed on the Exmouth Plateau northwest of the North West Cape in Western Australia in December 2014-January 2015. Acoustic data collected with this array were used to evaluate the corridor of the southbound migration of pygmy blue whales of the eastern Indian Ocean population. It is found that pygmy blue whales tended to travel southward much further away from the Western Australian coast, at distances of up to 400 km from shore, than that expected from data on their northbound migration. This is an important observation providing additional information on the migration pattern of pygmy blue whales, which is crucial for assessing their population and migration by passive acoustic means.

6.
Kardiol Pol ; 75(2): 101-107, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-27296285

RESUMO

BACKGROUND: The prevalence of hypertension in Kazakhstan is high, and the majority of patients are not adequately controlled. Treatment with renal artery denervation (RAD) could represent a useful therapeutic option for a subset of patients in Kazakhstan with resistant hypertension. AIM: To assess the impact of RAD in a cohort of patients from Kazakhstan with resistant hypertension. METHODS: Between March 2012 and December 2013, 63 patients underwent RAD at our tertiary care centre. Eligibility criteria were office blood pressure more than 160 mm Hg systolic (SBP) or more than 90 mm Hg diastolic (DBP) despite being treated with three or more antihypertensive medications, including a diuretic. Ambulatory blood pressure was measured at baseline and at month 12, and monitoring also included impact on insulin resistance and renal function. RESULTS: There were significant decreases of 25 ± 24 mm Hg for ambulatory SBP during the daytime and of 26 ± 23 mm Hg for ambulatory SBP during the nighttime (p < 0.0001). We observed significant decreases of 12 ± 14 mm Hg for ambula-tory daytime DBP and of 11 ± 14 mm Hg in ambulatory nighttime DBP (p < 0.0001). A decrease in creatinine clearance was observed from 100.2 ± 33.6 mL/min at baseline to 90.2 ± 22.8 mL/min at month 12 (p < 0.001). Homeostasis model assessment-insulin resistance (HOMA-IR) decreased from 3.0 ± 4.6 at baseline to 2.5 ± 3.7 at 12 months (p = 0.007). CONCLUSIONS: In this population RAD resulted in statistically and clinically significant blood pressure reduction at 12 months with minimal adverse events.


Assuntos
Vasoespasmo Coronário/cirurgia , Denervação/efeitos adversos , Hipertensão/cirurgia , Artéria Renal/inervação , Adulto , Idoso , Monitorização Ambulatorial da Pressão Arterial , Feminino , Humanos , Cazaquistão , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento
7.
J Steroid Biochem Mol Biol ; 165(Pt B): 293-304, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27449817

RESUMO

Recent studies suggest that progesterone may possess anti-tumorigenic properties. However, a growth-modulatory role of progestins in human cancer cells remains obscure. With the discovery of a new class of membrane progesterone receptors (mPRs) belonging to the progestin and adipoQ receptor gene family, it becomes important to study the effect of this hormone on proliferation of tumor cells that do not express classical nuclear progesterone receptors (nPRs). To identify a cell line expressing high levels of mPRs and lacking nPRs, we examined mRNA levels of nPRs and three forms of mPRs in sixteen human tumor cell lines of different origin. High expression of mPR mRNA has been found in pancreatic adenocarcinoma BxPC3 cells, while nPR mRNA has not been detected in these cells. Western blot analysis confirmed these findings at the protein level. We revealed specific binding of labeled progesterone in these cells with affinity constant similar to that of human mPR expressed in yeast cells. Progesterone at high concentration of 20 µM significantly reduced the mRNA levels of proliferation markers Ki67 and PCNA, as well as of cyclin D1, and increased the mRNA levels of cyclin dependent kinase inhibitors p21 and p27. Progesterone (1 µM and 20 µM) significantly inhibited proliferative activity of BxPC3 cells. These results point to anti-proliferative effects of the progesterone high concentrations on BxPC3 cells and suggest that activation of mPRs may mediate this action. Our data are a starting point for further investigations regarding the application of progesterone in pancreatic cancer.


Assuntos
Adenocarcinoma/metabolismo , Regulação Neoplásica da Expressão Gênica , Regulação da Expressão Gênica , Neoplasias Pancreáticas/metabolismo , Progesterona/farmacologia , Receptores de Progesterona/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Sobrevivência Celular , Ciclina D1/metabolismo , Células HeLa , Humanos , Células Jurkat , Antígeno Ki-67/metabolismo , Células MCF-7 , Antígeno Nuclear de Célula em Proliferação/metabolismo , Neoplasias Pancreáticas
8.
Rev Sci Instrum ; 87(2): 02B114, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26931996

RESUMO

The results of investigation of emission productivity of negative particles source with cesiated combined discharge are presented. A cylindrical beam of negative hydrogen ions with density about 2 A/cm(2) in low noise mode on source emission aperture is obtained. The total beam current values are up to 200 mA for negative hydrogen ions and up to 1.5 A for all negative particles with high divergence after source. The source has simple design and can produce stable discharge with low level of oscillation.


Assuntos
Ânions/química , Hidrogênio/química
9.
Chemosphere ; 120: 479-85, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25260045

RESUMO

The esterase paraoxonase (PON1), a major component of high-density lipoprotein (HDL), protects against the development of atherosclerosis in humans. Although variation in PON1 activity is primarily governed by PON1 genotype, there is growing evidence that environmental chemicals may also modulate its activity. This cross-sectional study aimed to determine whether environmental exposure to various metals is associated with PON1 activity in Inuit people routinely exposed to mercury (Hg), cadmium (Cd), lead (Pb), and (Se) selenium. PON1 activity and metal concentrations were measured in blood collected from 2172 healthy participants. Sociodemographic, anthropometric and lifestyle variables were also assessed. The associations between PON1 activity and blood metal concentrations, HDL, omega-3 fatty acid blood levels, age, sex, body mass index (BMI), and lifestyle habits (e.g. smoking and alcohol consumption) were explored via multiple linear regression. PON1 activity was positively associated with Se blood concentration (ß=0.056, P=0.001) but was negatively associated with Cd blood concentration (ß=-0.025, P<0.001). No association was observed between PON1 activity and Hg or Pb blood concentrations. Our results suggest that: PON1 activity is modulated by metal exposure, and Inuit traditional foods may confer health benefit by increasing PON1 activity via higher Se intakes. These findings underline that current environmental metal exposures among Inuit living in the Canadian Arctic are associated with paraoxonase activity, a toxicologically-relevant biochemical parameter.


Assuntos
Arildialquilfosfatase/sangue , Poluentes Ambientais/sangue , Metais Pesados/sangue , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Índice de Massa Corporal , Canadá/epidemiologia , Estudos Transversais , Monitoramento Ambiental , Ácidos Graxos Ômega-3/sangue , Feminino , Humanos , Inuíte , Estilo de Vida , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Adulto Jovem
10.
Environ Int ; 59: 33-40, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23770579

RESUMO

Inuit living in the Arctic are exposed to elevated levels of environmental contaminants primarily due to long-range atmospheric transport. Blood sampling and contaminant biomonitoring was conducted as part of the International Polar Year Inuit Health Survey in 2007-2008. The body burden of metals (e.g. Cd, Pb) and persistent organic pollutants (e.g. PCBs, DDT & DDE, toxaphene, chlordane, PBDEs) were measured for Inuit participants (n=2172) from 36 communities in Nunavut, Nunatsiavut, and the Inuvialuit Settlement Region, in Canada. The geometric mean of blood concentrations for Cd, Pb, PCBs, DDE & DDT, toxaphene, and chlordane were higher than those in the Canadian general population. A total of 9% of study participants exceeded the intervention guideline of 100µgL(-1) for Pb, 11% of participants exceeded the trigger guideline of 5µgL(-1) for Cd, and 1% exceeded the intervention guideline of 100µgL(-1) for PCBs. Also, 3% of women of child-bearing age exceeded blood Pb of 100µgL(-1) while 28% of women of child-bearing age exceeded 5µgL(-1) of PCBs. This work showed that most Inuit Health Survey participants were below blood contaminant guidelines set by Health Canada but that metal and POP body burdens commonly exceed exposures observed in the general population of Canada.


Assuntos
Exposição Ambiental , Poluentes Ambientais/sangue , Inuíte , Compostos Orgânicos/sangue , Adolescente , Adulto , Regiões Árticas , Carga Corporal (Radioterapia) , Clordano/sangue , Clordano/normas , Monitoramento Ambiental , Poluentes Ambientais/normas , Feminino , Guias como Assunto , Éteres Difenil Halogenados/sangue , Éteres Difenil Halogenados/normas , Humanos , Masculino , Metais/sangue , Metais/normas , Pessoa de Meia-Idade , Nunavut , Compostos Orgânicos/normas , Bifenilos Policlorados/sangue , Bifenilos Policlorados/normas , Adulto Jovem
11.
J Nutr ; 143(6): 923-30, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23616502

RESUMO

Elevated concentrations of mercury (Hg) are commonly found in the traditional foods, including fish and marine mammals, of Inuit living in Canada's Arctic. As a result, Inuit often have higher dietary Hg intake and elevated Hg blood concentrations. However, these same traditional foods are excellent sources of essential nutrients. The goals of this study were 1) to identify the traditional food sources of Hg exposure for Inuit, 2) to estimate the percentage of Inuit who meet specific nutrient Dietary Reference Intakes and/or exceed the Toxicological Reference Values (TRVs), and 3) to evaluate options that maximize nutrient intake while minimizing contaminant exposure. A participatory cross-sectional survey was designed in consultation with Inuit in 3 Canadian Arctic jurisdictions (Nunatsiavut, Nunavut, and the Inuvialuit Settlement Region). Estimated intakes for EPA (20:5n3) and DHA (22:6n3) met suggested dietary targets, and estimated selenium (Se) intake fell within the Acceptable Range of Oral Intake. Estimated intakes of Hg (rs = 0.41, P < 0.001), Se (rs = 0.44, P < 0.001), EPA (rs = 0.32, P < 0.001), and DHA (rs = 0.28, P < 0.001) were correlated with their respective blood concentrations. Mean estimated Hg intake (7.9 µg · kg(-1) · wk(-1)) exceeded the TRV of 5.0 µg · kg(-1) · wk(-1), with 35% of the population above this guideline. Because the estimated intakes of each of the nutrients were strongly correlated (Se: rs = 0.92, P < 0.001; EPA: rs = 0.82, P < 0.001; DHA: rs = 0.81, P < 0.001) with estimated Hg intake, efforts to decrease Hg exposure must emphasize the overall healthfulness of traditional foods and be designed to prevent concomitant harm to the nutrient intakes of Inuit.


Assuntos
Dieta , Ácidos Graxos Ômega-3/administração & dosagem , Educação em Saúde , Inuíte , Mercúrio/administração & dosagem , Selênio/administração & dosagem , Adolescente , Adulto , Animais , Regiões Árticas , Canadá , Estudos Transversais , Ácidos Docosa-Hexaenoicos/administração & dosagem , Ácido Eicosapentaenoico/administração & dosagem , Peixes , Humanos , Mercúrio/sangue , Mercúrio/toxicidade , Pessoa de Meia-Idade , Política Nutricional , Medição de Risco
12.
Rev Sci Instrum ; 84(2): 021101, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23464181

RESUMO

The fundamental principles, experimental results, and potential applications of the electrostatic plasma lens for focusing and manipulating high-current, energetic, heavy ion beams are reviewed. First described almost 50 years ago, this optical beam device provides space charge neutralization of the ion beam within the lens volume, and thus provides an effective and unique tool for focusing high current beams where a high degree of neutralization is essential to prevent beam blow-up. Short and long lenses have been explored, and a lens in which the magnetic field is provided by rare-earth permanent magnets has been demonstrated. Applications include the use of this kind of optical tool for laboratory ion beam manipulation, high dose ion implantation, heavy ion accelerator injection, in heavy ion fusion, and other high technology.

13.
Environ Health Perspect ; 119(3): 319-25, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21362590

RESUMO

BACKGROUND: Residents of Anniston, Alabama, live near a Monsanto plant that manufactured polychlorinated biphenyls (PCBs) from 1929 to 1971 and are relatively heavily exposed. OBJECTIVES: The goal of this study was to determine the relationship, if any, between blood pressure and levels of total serum PCBs, several PCB groups with common actions or structure, 35 individual PCB congeners, and nine chlorinated pesticides. METHODS: Linear regression analysis was used to determine the relationships between blood pressure and serum levels of the various contaminants after adjustment for age, body mass index, sex, race, smoking, and exercise in 394 Anniston residents who were not taking antihypertensive medication. RESULTS: Other than age, total serum PCB concentration was the strongest determinant of blood pressure of the covariates studied. We found the strongest associations for those PCB congeners that had multiple ortho chlorines. We found the associations over the full range of blood pressure as well as in those subjects whose blood pressure was in the normal range. The chlorinated pesticides showed no consistent relationship to blood pressure. CONCLUSIONS: In this cross-sectional study, serum concentrations of PCBs, especially those congeners with multiple ortho chlorines, were strongly associated with both systolic and diastolic blood pressure.


Assuntos
Pressão Sanguínea/efeitos dos fármacos , Compostos Clorados/sangue , Poluentes Ambientais/sangue , Praguicidas/sangue , Bifenilos Policlorados/sangue , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Compostos Clorados/toxicidade , Estudos Transversais , Poluentes Ambientais/toxicidade , Feminino , Humanos , Hipertensão/sangue , Hipertensão/epidemiologia , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Praguicidas/toxicidade , Bifenilos Policlorados/toxicidade , Adulto Jovem
14.
J Hypertens ; 28(10): 2053-60, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20644494

RESUMO

OBJECTIVE: To determine risk factors for elevated blood pressure and hypertension in residents of Anniston, Alabama who live near a plant that manufactured polychlorinated biphenyls (PCBs). METHODS: A total of 758 Anniston residents had multiple measurements of blood pressure, provided information on demographic factors, medications, smoking, and exercise, and provided blood samples for determination of PCBs and total serum lipid. RESULTS: Rates of hypertension increased significantly (P < 0.05) with age and concentration of serum PCBs and were higher in African-Americans (n = 351) than in whites (n = 407). Hypertension also increased with BMI, but was not related to total serum lipid, sex, smoking, or exercise. Among 394 persons not on antihypertensive medication, linear regression analysis demonstrated a significant positive relation between serum PCB level and both systolic and diastolic blood pressure. After adjustment for potentially confounding variables, logistic regression gave odds ratios for the highest to lowest tertiles of total serum PCBs that exceeded 3.5 for both systolic and diastolic hypertension. When analyzed by quintiles of PCBs, the highest odds ratio was in the third quintile, suggesting a low dose effect. CONCLUSION: In individuals not on antihypertensive medication, serum PCB levels were significantly associated with prevalence of hypertension. Significant positive associations were also observed between PCB concentrations and systolic and diastolic blood pressure even in normotensive ranges. The strength of the relationships between PCB exposure and both hypertension and blood pressure suggests that PCB exposure may be an important contributing factor in regulation of blood pressure.


Assuntos
Pressão Sanguínea/fisiologia , Hipertensão/epidemiologia , Hipertensão/fisiopatologia , Bifenilos Policlorados/sangue , Adolescente , Adulto , Negro ou Afro-Americano , Idoso , Idoso de 80 Anos ou mais , Alabama/epidemiologia , Estudos Transversais , Poluentes Ambientais/efeitos adversos , Feminino , Humanos , Hipertensão/induzido quimicamente , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Bifenilos Policlorados/efeitos adversos , Prevalência , Fatores de Risco , População Branca , Adulto Jovem
15.
J Aquat Anim Health ; 22(4): 280-90, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21413513

RESUMO

Levels of total mercury in yellow perch Perca flavescens from Adirondack lakes were studied in relation to characteristics of the lakes to determine why some lakes had fish with higher concentrations of mercury. Almost all mercury in fish is in the form of methylmercury, which can pose significant health hazards to humans who consume such fish. Fish mercury concentrations and water chemistry data were analyzed from eight Adirondack lakes. Four lakes (Halfmoon Lake, Sand Pond, Rock Pond, and Upper Sister Lake) had pH values of less than 5.0. Four other lakes (Lake Adirondack, Kings Flow, Harris Lake, and Lake Kushaqua) had pH values of more than 7.0. The acidic lakes also had high levels of aluminum and low acid-neutralizing capacity relative to the neutral lakes. Yellow perch (n = 100) from the acidic lakes had significantly higher levels of mercury than did those (n = 102) from the neutral lakes (P < 0.001), and the total mercury concentration increased with both length and weight of the fish. We conclude that the pH of the lake water is a major factor in determining the concentration of methylmercury in yellow perch.


Assuntos
Água Doce/química , Mercúrio/metabolismo , Percas/metabolismo , Poluentes Químicos da Água/metabolismo , Animais , Concentração de Íons de Hidrogênio , Mercúrio/química , New York , Poluentes Químicos da Água/química
16.
Environ Health Perspect ; 117(9): 1454-60, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19750113

RESUMO

BACKGROUND: Polychlorinated biphenyls (PCBs) and chlorinated pesticides are endocrine disruptors, altering both thyroid and estrogen hormonal systems. Less is known of action on androgenic systems. OBJECTIVE: We studied the relationship between serum concentrations of testosterone in relation to levels of PCBs and three chlorinated pesticides in an adult Native American (Mohawk) population. METHODS: We collected fasting serum samples from 703 adult Mohawks (257 men and 436 women) and analyzed samples for 101 PCB congeners, hexachlorobenzene (HCB), dichlorodiphenyldichloroethylene (DDE), and mirex, as well as testosterone, cholesterol, and triglycerides. The associations between testosterone and tertiles of serum organochlorine levels (both wet weight and lipid adjusted) were assessed using a logistic regression model while controlling for age, body mass index (BMI), and other analytes, with the lowest tertile being considered the referent. Males and females were considered separately. RESULTS: Testosterone concentrations in males were inversely correlated with total PCB concentration, whether using wet-weight or lipid-adjusted values. The odds ratio (OR) of having a testosterone concentration above the median was 0.17 [95% confidence interval (CI), 0.05-0.69] for total wet-weight PCBs (highest vs. lowest tertile) after adjustment for age, BMI, total serum lipids, and three pesticides. The OR for lipid-adjusted total PCB concentration was 0.23 (95% CI, 0.06-0.78) after adjustment for other analytes. Testosterone levels were significantly and inversely related to concentrations of PCBs 74, 99, 153, and 206, but not PCBs 52, 105, 118, 138, 170, 180, 201, or 203. Testosterone concentrations in females are much lower than in males, and not significantly related to serum PCBs. HCB, DDE, and mirex were not associated with testosterone concentration in either men or women. CONCLUSIONS: Elevation in serum PCB levels is associated with a lower concentration of serum testosterone in Native American men.


Assuntos
Poluentes Ambientais/sangue , Indígenas Norte-Americanos , Bifenilos Policlorados/sangue , Testosterona/sangue , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Índice de Massa Corporal , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Radioimunoensaio , Adulto Jovem
17.
Environ Res ; 106(2): 226-39, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18054906

RESUMO

We have investigated the relationships among the concentration of total serum polychlorinated biphenyls (PCBs), various PCB congener groupings, and three pesticides to total serum lipids in humans with and without self-reported cardiovascular disease. Blood samples were obtained from 335 adult Akwesasne Mohawks, and were analyzed for 101 PCB congeners, mirex, dichloro-diphenyl-dichloro-ethylene (DDE), and hexachlorobenzene (HCB), as well as serum triglycerides and cholesterol. Structural equation modeling, following the definition of latent variables by means of confirmatory factor analysis, was used to analyze the relationships between serum lipids with PCBs and heart disease. There were significant associations among PCBs, lipids, age, and body mass index (BMI), a fact which justified the application of the structural equation model. Gender of the participant was unrelated to any of the remaining study variables. The results of this study are consistent with a model in which age is considered as both an exogenous explanatory variable and a biological driving mechanism for the acquisition of PCBs. Moreover, the results of this study are consistent with the conclusion that PCBs, acting through P450 enzymes, are directly responsible for increased synthesis of cholesterol and triglycerides, substances known to be major risk factors for cardiovascular disease.


Assuntos
Doenças Cardiovasculares/epidemiologia , Exposição Ambiental/efeitos adversos , Poluentes Ambientais/sangue , Praguicidas/sangue , Bifenilos Policlorados/sangue , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Doenças Cardiovasculares/sangue , Doenças Cardiovasculares/etnologia , Doenças Cardiovasculares/etiologia , Colesterol/sangue , Monitoramento Ambiental , Monitoramento Epidemiológico , Feminino , Humanos , Indígenas Norte-Americanos/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , New York/epidemiologia , Análise de Regressão , Triglicerídeos/sangue
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