Publications by authors named "Marcia Racines-Orbe"

9 Publications

  • Page 1 of 1

promoter DNA-methylation level and glucose metabolism in Ecuadorian women with Turner syndrome.

Horm Mol Biol Clin Investig 2020 Dec 22;42(2):159-165. Epub 2020 Dec 22.

Institute of Biomedicine Research, Central University of Ecuador, Quito, Ecuador.

Objectives: Reduced gene expression of in subjects with insulin resistance (IR) has been reported. Insulin resistance occurs early on the course of Turner syndrome (TS). The main objective of this study was to evaluate the relationship between promoter DNA methylation status in lymphocytes and insulin sensitivity and secretion in Ecuadorian females with TS.

Methods: We examined a cohort of 34 Ecuadorian patients with TS along with a sex-, age- and BMI-matched reference group. All subjects received a standard 75 g oral glucose tolerance test. Insulin resistance and secretion indices were calculated. The methylated DNA/unmethylated DNA ratio and mitochondrial content (mtDNA/nDNA ratio) were further determined.

Results: Notably, the DNA methylation level was significantly higher in TS subjects than the reference group and correlated with IR indices. Conversely, mitochondrial content was significantly lower in the study group than healthy controls and negatively correlated with the methylated DNA/unmethylated DNA ratio in TS individuals. promoter DNA methylation status contributed to 20% of the total variability in Homeostasis Model Assessment for Insulin Resistance (HOMA-IR) independently of BMI or age in TS subjects.

Conclusions: Our collective findings suggest that expression of and lower mitochondrial number affect the metabolic phenotype in TS subjects.
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December 2020

Elevated blood lead and metal/metalloid levels and environmental exposure sources in urban Ecuadorian school-age children and mothers.

Int J Hyg Environ Health 2021 06 24;235:113770. Epub 2021 May 24.

Biomedical Research Institute, Central University of Ecuador, Quito, Ecuador.

Background: Lead and other toxic and potentially toxic metals and metalloids are significant contributors to the global burden of disease and disability. Studies characterizing blood metal/metalloid levels and potential sources of environmental exposures are limited for populations living in the major urban centers of Andean-area countries.

Methods: We used ICP-MS to quantify blood levels of lead (PbB), cadmium (CdB), manganese (MnB), total arsenic (AsB), and total mercury (HgB) in school-age children (n = 47) and their reproductive-age mothers (n = 49) from low-resource households in Quito, Ecuador. These were compared to published 95th percentile reference values (RV) and for PbB, also to CDC reference values. We used a detailed environmental questionnaire to examine the contribution of residential and neighborhood environmental exposure sources with participant blood metal/metalloid levels. We used ICP-MS to measure Pb levels in residential windowsill dust, floor dust, and drinking water samples and used XRF for paint samples.

Results: Forty-five percent of the mothers had PbBs ≥ 5 μg/dL; 14.3% had PbBs ≥10 μg/dL. Maternal blood levels exceeded RV for PbB (76%), CdB (41%), MnB (88%), HgB (57%), and AsB (90%). Of children, 68% had PbBs ≥ 5 μg/dL, and 21.3% had PbB ≥10 μg/dL. Most child blood levels exceeded the RV for PbB (100%), CdB (100%), MnB (94%), and total HgB (94%) and AsB (98%). Most mothers (97%) and all children had blood levels indicating exposure to multiple metal/metalloid mixtures. Maternal and child PbBs were moderately correlated with each other but the other four metals/metalloids were not. Factors associated with maternal blood metal/metalloid levels were residence in a home with an earthen floor (PbB) or bare cement block walls (MnB), living near a dirt-paved or cobblestone street (PbB), <50 m from a heavily trafficked major roadway (PbB, HgB), living in the Los Chillos (PbB) or Cotocollao neighborhoods (PbB, HgB), or in areas where street vendors grilled food using charcoal (MnB). Factors associated with child blood metal/metalloid levels were residence in a dirt floor home (PbB, CdB, AsB), living near a dirt-paved or cobblestone street (PbB), living in the El Camal or Cotocollao neighborhoods (AsB), or in local neighborhoods where scrap metal smelters (MnB) and LPG gas depositories (PbB) were present.

Conclusions: The elevated blood levels of PbB, other metal/metalloids, and metal/metalloid mixtures identified mothers and children in this exploratory study is an urgent public health and clinical concern. The exposure patterns suggest that traffic-related exposures, especially the resuspension of legacy Pb in dust, as well as other anthropogenic and geogenic sources may be important environmental contributors to metal/metalloid exposures in urban Ecuadorian mothers and children. Future studies are needed to confirm these findings and explore other potential exposure sources. Biomonitoring is also needed in order to formulate effective intervention strategies to reduce population exposure to toxic levels of environmental metals/metalloids.
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June 2021

Insulin Sensitivity and Pancreatic β-Cell Function in Ecuadorian Women With Turner Syndrome.

Front Endocrinol (Lausanne) 2020 7;11:482. Epub 2020 Aug 7.

Faculty of Biological Sciences, Biological Sciences School, Central University of Ecuador, Quito, Ecuador.

To assess insulin sensitivity and pancreatic β-cell function in an adult population of Ecuadorian individuals with Turner syndrome (TS). This was a cross-sectional correlational study conducted in TS subjects (>20 years old; = 38). A standard 2-h oral glucose tolerance test was performed in both women with TS and the reference group. Glucose, lipids, insulin, and C-peptide concentrations were measured. Homeostasis Model Assessment (HOMA) of Insulin Resistance, Quantitative Insulin Sensitivity Check Index, McAuley, Matsuda, and Belfiore indices were calculated to evaluate the degree of insulin resistance (IR). The pancreatic β-cell function was assessed using HOMA-β, basal C-Peptide Index (CPI), and CPII at 120'. A higher prevalence of impaired glucose tolerance was found in TS subjects compared with the reference group. Although significant differences were found for glucose concentrations at 60' and 120' (but not at 0'), only the baseline insulin concentrations differed significantly between the two groups. The values of the IR indices were statistically different between study and reference groups. A significant number of TS subjects diagnosed with IR were differently classified according to the index applied. The concentrations of C-peptide at 0' and 120' of TS subjects were similar to those of the control group. In contrast, the CPI and CPII values in the study group were significantly lower than those in the control group. It is impossible to select the best surrogate method for the assessment of IR in women with TS. The CPI and CPII values could be preferable to other indices to assess the pancreatic β-cell function in TS subjects. Our findings suggest that IR and pancreatic β-cell dysfunction could be independent events in women with TS, and both conditions seem to be caused by the disease . Our results imply that early screening and intervention for TS would be therapeutic for TS women.
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May 2021

Metabolic Syndrome as a Risk Factor for Sensorineural Hearing Loss in Adult Patients with Turner Syndrome.

Appl Clin Genet 2020 13;13:25-35. Epub 2020 Jan 13.

Pediatric Endocrine Unit, Hospital De Clinicas Caracas, Caracas, Venezuela.

Background And Purpose: Metabolic syndrome (MetS) is a disorder associated with an increased risk of cardiovascular disease. The frequency of each component of MetS in Turner syndrome (TS) subjects is high. An elevated incidence of hearing loss has also been reported in TS. Sensorineural hearing loss (SNHL) affects at least half of young women with TS. The association between MetS and SNHL has not been previously considered in TS. The aim of this study is to evaluate the association between these two conditions.

Patients And Methods: Cross-sectional anthropometric, cardio-metabolic and audiological data were obtained from a cohort consisting of unrelated TS subjects (>20 years of age; n = 93). Metabolic syndrome was defined according to the International Diabetes Federation criteria. Types and severity of hearing loss were based on the American Speech Hearing Association guidelines.

Results: Hearing loss was detected in 74% of ears from adult TS subjects and SNHL was observed in half of our TS subjects. The prevalence of MetS in TS subjects with or without SNHL was 64% and 11%, respectively (P < 0.05). After adjusting for age, MetS was related to a ninefold increase in the odds of SNHL. This odds increased in a stepwise manner as the number of MetS components increased.

Conclusion: MetS and its individual components were associated factors for SNHL in TS subjects. A reduction in the number and severity of the components of MetS might potentially contribute to decreasing the progression of SNHL at younger ages, but further studies will be needed to explain the underlying pathological mechanism connecting MetS and SNHL.
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January 2020

Mass Administration of Ivermectin for the Elimination of Onchocerciasis Significantly Reduced and Maintained Low the Prevalence of Strongyloides stercoralis in Esmeraldas, Ecuador.

PLoS Negl Trop Dis 2015 Nov 5;9(11):e0004150. Epub 2015 Nov 5.

Centro per le Malattie tropicali, Ospedale Sacro Cuore, Negrar (Verona), Italy.

Objectives: To evaluate the effect of ivermectin mass drug administration on strongyloidiasis and other soil transmitted helminthiases.

Methods: We conducted a retrospective analysis of data collected in Esmeraldas (Ecuador) during surveys conducted in areas where ivermectin was annually administered to the entire population for the control of onchocerciasis. Data from 5 surveys, conducted between 1990 (before the start of the distribution of ivermectin) and 2013 (six years after the interruption of the intervention) were analyzed. The surveys also comprised areas where ivermectin was not distributed because onchocerciasis was not endemic. Different laboratory techniques were used in the different surveys (direct fecal smear, formol-ether concentration, IFAT and IVD ELISA for Strongyloides stercoralis).

Results: In the areas where ivermectin was distributed the strongyloidiasis prevalence fell from 6.8% in 1990 to zero in 1996 and 1999. In 2013 prevalence in children was zero with stool examination and 1.3% with serology, in adult 0.7% and 2.7%. In areas not covered by ivermectin distribution the prevalence was 23.5% and 16.1% in 1996 and 1999, respectively. In 2013 the prevalence was 0.6% with fecal exam and 9.3% with serology in children and 2.3% and 17.9% in adults. Regarding other soil transmitted helminthiases: in areas where ivermectin was distributed the prevalence of T. trichiura was significantly reduced, while A. lumbricoides and hookworms were seemingly unaffected.

Conclusions: Periodic mass distribution of ivermectin had a significant impact on the prevalence of strongyloidiasis, less on trichuriasis and apparently no effect on ascariasis and hookworm infections.
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November 2015

Maternal plasma and amniotic fluid coenzyme Q10 levels in preterm and term gestations: a pilot study.

Arch Gynecol Obstet 2011 Mar 29;283 Suppl 1:67-71. Epub 2011 Mar 29.

Centro de Biomedicina, Universidad Central del Ecuador, Quito, Ecuador.

Objective: To measure maternal plasma and amniotic fluid coenzyme Q10 (CoQ10) levels in preterm and term gestations.

Study Design: This pilot study comprised a convenience sample of 72 women admitted for labor with singleton live gestations and intact membranes (preterm n = 27 and term n = 45).

Results: Median [interquartile range] maternal plasma CoQ10 levels did not differ among the studied women (preterm, 0.47 [0.12] vs. term, 0.47 [0.23] mmol/L, p = 0.90). Overall CoQ10 amniotic fluid levels were nearly tenfold lower than those found in maternal plasma, with a significant lower level observed among those delivering preterm (0.050 [0.05] vs. 0.062 [0.04] mmol/L, p = 0.007). Multiple linear regression analysis controlling for several covariates determined a significant correlation between amniotic fluid CoQ10 levels and neonatal gestational age.

Conclusion: This is the first study to assess CoQ10 levels in amniotic fluid during pregnancy in which levels were significantly lower among those delivering preterm. More research is warranted in this regard.
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March 2011

Coenzyme Q10 levels in women with preeclampsia living at different altitudes.

Biofactors 2008 ;32(1-4):185-90

Biomedical Center, Central University of Ecuador, Quito, Ecuador.

Background: Preeclampsia is a common disorder of pregnancy exhibiting abnormal plasma and placental coenzyme Q10 (CoQ10) levels when compared to normal pregnancies.

Objective: To evaluate CoQ10 levels both in plasma and placenta among normal pregnant (n = 60) and preeclamptic (n = 63) primigravid women and determine the effect of high or low altitude residency.

Study Design: CoQ10 was determined using High Performance Liquid Chromatography (HPLC) technique and group comparisons were performed.

Results: Preeclamptic women living at high altitude displayed significantly lower CoQ10 plasma levels (0.64 +/- 0.23 vs. 0.82 +/- 0.46 micromol/L, p = 0.05). No differences were found in CoQ10 plasma levels among women living at sea level. Interestingly, plasma CoQ10 levels at low altitude in normal pregnancies were significantly lower than high altitude normal pregnancies. Compared to normal pregnancies, preeclamptic women displayed higher placental CoQ10 content, which was only significant among those living at sea level (0.120 +/- 0.07 vs. 0.076 +/- 0.04 ng/mg protein, p < 0.005). Normal pregnant women living at high altitude displayed higher placental CoQ10 content when compared to those residing at sea level (p < 0.0005).

Conclusion: Women suffering from preeclampsia (high or low altitude) display high placental CoQ10 content, with significant low plasma CoQ10 levels among those residing in high altitude. More research is warranted to establish the cause-effect relationship between CoQ10 levels and preeclampsia.
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February 2009

Coenzyme Q10 is increased in placenta and cord blood during preeclampsia.

Biofactors 2005 ;25(1-4):153-8

Experimental Pharmacology and Cellular Metabolism Unit, Biomedical Center, Central University of Ecuador, Quito.

Preeclampsia is a common (approximately 7% of all pregnancies) disorder of pregnancy in which the normal hemodynamic response to pregnancy is compromised. Despite many years of intensive research, the pathogenesis of preeclampsia is still not fully understood. The objective of the present study was to investigate the levels of coenzyme Q(10) (CoQ(10)) in placental tissue compared to maternal and umbilical cord levels both during normal pregnancy and in those complicated with preeclampsia. Pregnant women (n = 30) and women with preeclampsia (n = 30) were included. Maternal, newborn cord blood levels and placental content of coenzyme Q(10) were measured by high performance liquid chromatography (HPLC). Plasma coenzyme Q(10) levels were significantly higher in normal pregnant women than in women with preeclampsia. CoQ(10) content in placenta from women with preeclampsia (mean 0.28 SEM 0.11 nmol/mg protein) was significantly higher compared to normal pregnancy (mean 0.09 SEM 0.01 nmol/mg protein; p = 0.05). Levels of CoQ(10) in cord blood from normal pregnant women (mean 0.30 SEM 0.05 micromol/l) were significantly lower than in preeclamptic women (mean 4.03 SEM 2.38 micromol/l). In conclusion, these data indicate a possible involvement of CoQ(10) in preeclampsia that might bear deep physiopathological significance and deserve to be further elucidated.
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October 2006

Preeclampsia is associated with a decrease in plasma coenzyme Q10 levels.

Free Radic Biol Med 2003 Dec;35(11):1453-6

Experimental Pharmacology and Cellular Metabolism Unit, Biomedical Center, Central University of Ecuador, Quito, Ecuador.

Preeclampsia is a common ( approximately 7% of all pregnancies) disorder of human pregnancy in which the normal hemodynamic response to pregnancy is compromised. Despite many years of intensive research, the pathogenesis of preeclampsia is still not fully understood. The objective of the present study was to investigate the concentration of coenzyme Q10 in normal pregnancy and preeclampsia. Pregnant women (n = 18), women with preeclampsia (n = 12), and nonpregnant normotensive women (n = 22) were included. Plasma levels of coenzyme Q10 were measured by high-performance liquid chromatography. Plasma coenzyme Q10 levels were significantly higher in normal pregnant women (mean = 1.08, SEM = 0.08 umol/l; p <.005) in comparison to nonpregnant women (mean = 0.86, SEM = 0.16 umol/l) and women with preeclampsia (mean = 0.7, SEM = 0.03 umol/l; p <.0001). These results demonstrated that during preeclampsia there is a significant decrease in plasma levels of coenzyme Q10 compared to normal pregnant women, and compared to those who are not pregnant.
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December 2003