Alvarado-Esquivel C.,Mexico State University
PLoS ONE | Year: 2013
Background: The epidemiology of Toxocara infection in humans in Mexico has been poorly explored. There is a lack of information about Toxocara infection in waste pickers. Aims: Determine the seroepidemiology of Toxocara infection in waste pickers. Methods: Through a case control study design, the presence of anti-Toxocara IgG antibodies was determined in 90 waste pickers and 90 age- and gender-matched controls using an enzyme-linked immunoassay. Associations of Toxocara exposure with socio-demographic, work, clinical, and behavioral data of the waste pickers were also evaluated. Results: The seroprevalence of anti-Toxocara IgG antibodies was significantly higher in waste pickers (12/90: 13%) than in control subjects (1/90: 1%) (OR = 14; 95% CI: 2-288). The seroprevalence was not influenced by socio-demographic or work characteristics. In contrast, increased seroprevalence was found in waste pickers suffering from gastritis, and reflex and visual impairments. Multivariate analysis showed that Toxocara exposure was associated with a low frequency of eating out of home (OR = 26; 95% CI: 2-363) and negatively associated with consumption of chicken meat (OR = 0.03; 95% CI: 0.003-0.59). Other behavioral characteristics such as animal contacts or exposure to soil were not associated with Toxocara seropositivity. Conclusions: 1) Waste pickers are a risk group for Toxocara infection. 2) Toxocara is impacting the health of waste pickers. This is the first report of Toxocara exposure in waste pickers and of associations of gastritis and reflex impairment with Toxocara seropositivity. Results warrant for further research. © 2013 Cosme Alvarado-Esquivel.
Alvarado-Esquivel C.,Mexico State University |
Estrada-Martinez S.,Mexico State University
Parasites and Vectors | Year: 2011
Background: We performed a retrospective, observational study in 1156 adult subjects from the general population of Durango City, Mexico, Fifty five subjects with a history of abdominal hernia repair and 1101 subjects without hernia were examined with enzyme-linked immunoassays for the presence of anti-Toxoplasma IgG and IgM antibodies. Results: The seroprevalence of anti-Toxoplasma IgG antibodies and IgG titers was significantly higher in subjects with abdominal hernia repair than those without hernia. There was a tendency for subjects with hernia repair to have a higher seroprevalence of anti-Toxoplasma IgM antibodies than subjects without hernia. The seroprevalence of anti-Toxoplasma IgG antibodies in subjects with hernia repair was significantly higher in subjects ≥50 years old than those < 50 years old. Further analysis in subjects aged ≥50 years showed that the seroprevalence of anti-Toxoplasma IgG antibodies was also significantly higher in individuals with hernia repair than those without hernia (OR = 2.72; 95% CI: 1.10-6.57). Matching by age and sex further showed that the seroprevalence of Toxoplasma infection was significantly higher in patients with hernia repair than those without hernia (OR: 4.50; 95% CI: 1.22-17.33). Conclusions: Results indicate that infection with Toxoplasma is associated with abdominal hernia. The contributing role of infection with Toxoplasma in abdominal hernia was observed mainly in subjects aged ≥50 years old. Our results might have clinical, prevention and treatment implications and warrant for further investigation. © 2011 Alvarado-Esquivel and Estrada-Martínez; licensee BioMed Central Ltd.
De La O Serna J.A.,Mexico State University |
Rodriguez-Maldonado J.,Mexico State University
IEEE Transactions on Power Systems | Year: 2011
The state-transition matrix of the Kth order Taylor approximation to the dynamic phasor and its first derivatives leads to a plurality of state-space representations to approach the bandpass signal model of a power oscillation. With these truncated signal models, the Kalman filter algorithm can be applied to their state vectors in order to find observers able to estimate the dynamic phasor and its first derivatives. The estimates obtained through this technique, from oscillatory signals, are not only instantaneous (no delay) but also synchronous, an important attribute for control applications. They also provide frequency estimates. The new filters reduce the total vector error achieved with the traditional Kalman filter; are much more stable, with settling times five times lower; and improve the phasor estimates of oscillations with frequency offset. © 2006 IEEE.
Alvarado-Esquivel C.,Mexico State University
Journal of Helminthology | Year: 2014
The epidemiology of toxocariasis in humans in Mexico has been poorly explored. There is a lack of information about toxocariasis in Tepehuanos, an indigenous ethnic group in Durango State in northern Mexico. Therefore, the presence of anti-Toxocara immunoglobulin (Ig) G antibodies was determined in 126 rural Tepehuanos using an enzyme-linked immunoassay. Socio-demographic, clinical and behavioural data of the participants were also obtained. Of the 126 Tepehuanos assessed (mean age 32.46 ± 17.36 years), 33 (26.2%) had anti-Toxocara IgG antibodies. Multivariate analysis showed that Toxocara seropositivity was associated with unemployment (students and housewives) (odds ratio (OR) = 3.1; 95% confidence interval (CI) 1.25-7.47). Other socio-demographic and behavioural characteristics, including age, educational level, contact with animals or soil, consumption of unwashed raw fruits and vegetables or untreated water, were not associated with Toxocara seropositivity. Clinical data were similar in seropositive and seronegative Tepehuanos. These results indicate that Toxocara exposure is common among Tepehuanos but Toxocara does not appear to impact on the health of the population. This is the first report of toxocaral infection in Tepehuanos, and of an association of toxocariasis in adults with unemployment. Further research is needed to elucidate the routes of transmission of Toxocara in Tepehuanos, including the role of hygiene practices, canine and feline contacts, paratenic hosts and soil contamination with infective Toxocara eggs. © 2013 Cambridge University Press.
Nowicki P.D.,Mexico State University
Journal of Pediatric Orthopaedics | Year: 2015
BACKGROUND:: Routine prophylactic screw fixation for skeletally immature patients with slipped capital femoral epiphysis (SCFE) continues to be debated. The purpose of this study was to assess the slip severity of a second SCFE in skeletally immature versus more mature patients and determine necessity of contralateral hip prophylactic screw fixation. METHODS:: All patients treated for SCFE at 3 pediatric hospitals over a 10-year time period (January 1, 2002 to December 31, 2011) were evaluated. Patients were included if they had a unilateral SCFE and a contralateral asynchronous SCFE, and were divided into immature (Oxford triradiate score 1) versus more mature (Oxford triradiate score 2 and 3) groups. Data evaluation included age, time between slips, body mass index, Southwick angles of first then second SCFEs, and follow-up duration. RESULTS:: There were a total of 45 patients: 16 patients in the skeletally immature and 29 patients in the more mature group. Average age at first SCFE in immature patients was 10.9 years and in more mature patients 12.1 years (P=0.70). Age at second SCFE in immature patients was 11.5 years and in more mature patients 13.0 years (P=0.023). Average time between SCFEs was 6.6 months for immature and 11.4 months for more mature patients (P=0.093). Southwick angles for immature patient first and second SCFEs were 25 and 12.9 degrees, respectively, and for more mature patient first and second SCFEs were 31 and 21 degrees, respectively. Southwick angles were higher at first and second slips in the more mature group, significant only at the second slip (P=0.032). SCFE severity at initial event was predictive of severity of second SCFE regardless of maturity (P=0.043). Regression analysis of slip severity against multiple patient factors demonstrated triradiate score was not a factor assessing subsequent SCFE magnitude (P=0.099). CONCLUSIONS:: There was no significant difference between first and second SCFEs regardless of skeletal maturity but severity of initial SCFE did correlate with severity of the second SCFE. Deciding not to prophylactically pin an unaffected hip does not lead to worse deformity if a second SCFE occurs in skeletally immature or more mature patients, unless the initial event is severe. Prophylactic pin fixation in skeletally immature patients should occur as a shared decision between patient, guardians, and treating surgeon. LEVEL OF EVIDENCE:: Level III—retrospective comparative study. Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.
Alvarado-Esquivel C.,Mexico State University
PLoS ONE | Year: 2013
Background: There is poor knowledge about the epidemiology of toxocariasis in psychiatric patients. Aims: Determine the seroepidemiology of Toxocara infection in psychiatric patients. Methods: Through a case-control seroprevalence study, 128 psychiatric inpatients and 276 control subjects were compared for the presence of anti-Toxocara IgG antibodies in Durango, Mexico. Socio-demographic, clinical, and behavioral characteristics of inpatients associated with toxocariasis were also investigated. Results: Six of the 128 (4.7%) psychiatric inpatients, and 3 (1.1%) of the 276 controls were positive for anti-Toxocara IgG antibodies (P = 0.03). Stratification by age showed that Toxocara seroprevalence was significantly (P = 0.02) higher in patients aged ≤50 years old (6/90:6.7%) than controls of the same age (2/163:1.2%). While Toxocara seroprevalence was similar in patients and controls aged >50 years old. Stratification by gender showed that Toxocara seroprevalence was significantly (P = 0.03) higher in female patients (2/37:5.4%) than in female controls (0/166:0%). No statistically significant associations between Toxocara seropositivity and clinical characteristics were found. In contrast, Toxocara seropositivity was associated with consumption of goat meat and raw sea snail. Conclusions: This is the first report of toxocariasis in psychiatric inpatients in Mexico. Further studies with larger sample sizes are needed to elucidate the association of toxocariasis with psychiatric diseases. The role of the consumption of goat meat and raw sea snail in the transmission of Toxocara deserve further investigation. © 2013 Cosme Alvarado-Esquivel.
Forster-Cox S.C.,Mexico State University
Health promotion practice | Year: 2010
The Environmental Health/Home Safety Education Project (Proyecto de Salud Ambiental y Seguridad en el Hogar) has been developed in response to a wide array of severe and often preventable environmental health issues occurring in and around homes on the U.S.-Mexico border. Utilizing well-trained community members, called promotoras , homes are visited and assessed for potential environmental hazards, including home fire and food safety issues. Data analyzed from project years 2002 to 2005 shows a significant impact in knowledge levels and initial behavior change among targeted participants as it relates to fire and food safety issues. Since the initiation of the project in 1999, hundreds of participants have improved their quality of life by making their homes safer. The project has proven to be sustainable, replicable, flexible, and attractive to funders.
Mendieta Zeron H.,Mexico State University
Acta medica (Hradec Králové) / Universitas Carolina, Facultas Medica Hradec Králové | Year: 2012
Leptin is an adipokine which has a direct relationship to obesity. Our aim was to measure this hormone in pregnant women at three months intervals throughout their pregnancies to determine the serum value of those who developed preeclampsia. We followed 19 women (median age 24.8 +/- 5.7 years) with pre-gestational Body Mass Index (BMI) less than 25 kg/m2, 21 (median age 26.1 +/- 4.6 years) with BMI higher than 25 kg/m2 and 16 (median age 30.9 +/- 5.8 years) with Gestational Diabetes Mellitus (GDM) (median age 30.9 +/- 5.8 years), recruited in the 1st trimester of pregnancy. Serum levels of leptin were measured with radioimmunoassay (RIA) technique. In the first trimester of pregnancy leptin levels showed statistically significant differences between normal weight and overweight-obese women (p < 0.001), diabetic women (p < 0.05) and the subgroup of preeclamptic women (p < 0.001). For those women with PGBMI > or = 40 kg/m2 and leptin > or = 40 ng/ml in the second trimester, the Odds Ratio (OR) to develop preeclampsia was of 47.95% CI (4.1-527.2). Analyzing leptin values with ROC curves, the greatest area under the curve (AUC) was for leptin in the second trimester (0.773, CI: 0.634-0.911). Women with morbid obesity (BMI > or = 40 kg/m2) had significantly higher levels of serum leptin (p < 0.01) and a value of 40 ng/ml of this hormone seems to be predictive of developing preeclampsia in this group of patients.
Platas-Garza M.A.,Mexico State University |
De La O Serna J.A.,Mexico State University
IEEE Transactions on Instrumentation and Measurement | Year: 2010
Estimates of the dynamic phasor and its derivatives are obtained through the weighted least squares solution of a Taylor approximation using classical windows as weighting factors. This solution leads to differentiators with ideal frequency response around the fundamental frequency and to very low sidelobe level over the stopband, which implies low noise sensitivity. The differentiators are maximally flat in the interval centered at the fundamental frequency and have a linear phase response. Therefore, their estimates are free of amplitude and phase distortion and are obtained at once. No further patch is needed to improve their accuracy. Examples of dynamic phasor estimates are illustrated under transient conditions. Special emphasis is put on frequency measurements. © 2006 IEEE.
Alvarado-Esquivel C.,Mexico State University
Helicobacter | Year: 2013
Background: The epidemiology of Helicobacter pylori infection among Mennonites (an ethnic group of German descent living in rural communities in Mexico) has not been previously studied. Materials and Methods: The prevalence of anti-H. pylori IgG antibodies was examined in 152 Mennonite individuals in Durango State, Mexico, using enzyme-linked immunoassays. Seroprevalence association with sociodemographic, clinical, and behavioral characteristics of the Mennonite community was also investigated. Results: In total, 77 (50.7%) of the 152 Mennonite participants (mean age, 38.4 ± 15.5 years) had H. pylori IgG antibodies, 35 (45.4%) of whom had H. pylori IgG antibody levels higher than 100 U/mL. Males and females had comparable seroprevalence rates of H. pylori and H. pylori IgG antibody levels. On the other hand, seroprevalence of H. pylori increased significantly with age and was significantly higher among women with history of deliveries and abortions than among those with no such obstetric characteristics. Logistic regression analysis of behavioral characteristics showed that H. pylori infection was associated with a low frequency of eating at restaurants and at fast food outlets (up to 10 times/year) (OR = 2.77; 95% CI: 1.28-5.98; p = .009), and eating meat (up to 3 days/week) (OR = 2.84; 95% CI: 1.36-5.91; p = .005). Conclusions: This is the first report on the seroprevalence of H. pylori among Mennonites, factors contributing to such infection, and the association of H. pylori infection with abortions and low frequencies of eating out of home and meat. Further research should be conducted on this topic. © 2013 John Wiley & Sons Ltd.