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The validity of soil toxicity databases for predicting ecological impacts in the field is rarely explored. The present study was set up to test whether laboratory toxicity data and the combined concepts of metal availability and mixture toxicity can predict ecological impact in mining‐affected soils. Metal and As contamination gradients were sampled approximately 5 different mines in Mexico where plant cover and abundances exhibited clear dose‐related responses. Soils were analyzed for total and isotopically exchangeable (labile) concentrations of Ni, Cu, Cd, Pb, and As and for soil properties affecting the availability of these elements. Six different indices of toxic doses were compared to evaluate their accuracy in describing the field response expressed as relative abundance and cover. Each index was based on a different method to calculate the sum of toxic units (ΣTUs) in soil, with 1 toxic unit equal to the concentration of the element in soil yielding 50% adverse effect on plants with median sensitivity as recorded in a recent database of salt‐spiked soils. Toxic concentrations in the mine‐impacted soils were dominated by Zn and As. In the field, 50% reduced cover or abundance was found at 10 to 13 ΣTUs if these were based on total soil concentrations and thresholds derived from freshly spiked soils, indicating a largely overestimated toxic effect. If thresholds were corrected for differences in availability among freshly spiked soils and spiked and laboratory‐aged soils, the overestimation of field toxicity was 5‐ to 6‐fold, irrespective of the consideration of soil properties. Finally, the ΣTU calculated only with labile metals and As overestimated the field toxicity by factors 1.1 to 1.6 (95% confidence interval 1–7; i.e., rather accurate and indicating some Zn–As antagonism as confirmed in experimental studies). That latter index of dose yielded a bell‐shaped response on species richness peaking at approximately 1.6 ΣTU. Overall, the present study shows that the current toxicity databases of metals can predict the impact of metal contamination on plant communities within factor 2, expressing the dose as soil‐labile concentrations and using the concentration addition concept in these mixed polluted environments. Environ Toxicol Chem 2020;39:1826–1838. © 2020 SETAC [ABSTRACT FROM AUTHOR]

The objective of this study was to determine the levels of organochlorine pesticides HCB, α-β-γ-HCH, p,p′-DDE, o,p′-DDT and p,p′-DDT in 150 adipose tissue of inhabitants of Tabasco, Mexico. The following pesticides were detected: p,p′-DDE in 100 % of samples at mean 1.034 mg/kg; p,p′-DDT in 96.7 % at mean 0.116 mg/kg; o,p′-DDT in 78.7 % at mean 0.022 mg/kg and β-HCH in 58.0 % at mean 0.049 mg/kg. The pooled sample was divided according to sex of donors (75 female and 75 male). Significantly higher levels of all organochlorine pesticides in females were found. The sample was divided into three age's ranges (15-28, 29-45 and 46-84 years). The mean and median levels of β-HCH, p,p'-DDE and Σ-DDT increase significantly ( p < 0.05) from the first to the second and third group. The presence of organochlorine pesticide residues in Tabasco inhabitants is still observed, indicating sources of exposure to the pesticides. [ABSTRACT FROM AUTHOR]

The objective of the present study was to monitor the levels of organochlorine pesticides HCB; α-, β-, γ-HCH; pp′DDE; op′DDT; and pp′DDT in blood serum of Veracruz, Mexico inhabitants. Organochlorine pesticides were analyzed in 150 blood serum samples that constituted that which remained after clinical analyses, using gas chromatography-electron-capture detection (GC-ECD). The results were expressed as milligrams per kilogram on fat basis and micrograms per liter on wet weight. Only the following pesticides were detected: p,p′-DDE was the major organochlorine component, detected in 100% of samples at mean 15.8 mg/kg and 8.4 μg/L; p,p′-DDT was presented in 41.3.% of monitored samples at mean 3.1 mg/kg and 1.4 μg/L; β-HCH was found in 48.6% of the samples at mean 4.9 mg/kg and 2.7 μg/L; op′DDT was determined to be in only 3.3% of monitored samples at mean 2.7 mg/kg and 1.4 μg/L. The pooled samples divided according to sex showed significant differences of β-HCH and pp′DDE concentrations in females. The samples grouped according to age presented the third tertile as more contaminated in both sexes, indicating age as a positively associated factor with serum organochlorine pesticide levels in Veracruz inhabitants. [ABSTRACT FROM AUTHOR]

The objective of this study was to determine the levels of organochlorine pesticides HCB, α- β-γ-HCH, pp′DDE, op′DDT and pp′DDT in adipose tissue of females living in Puebla, Mexico. Organochlorine pesticides were analyzed in 75 abdominal adipose tissue samples taken during 2010 by autopsy at the Forensic Services of Puebla. The results were expressed as mg/kg on fat basis. In analyzed samples the following pesticides were detected: p,p'-DDE in 100% of samples at mean 1.464 mg/kg; p,p'-DDT in 96.0.% of samples at mean 0.105 mg/kg; op′DDT in 89.3% of monitored samples at mean 0.025 mg/kg and β-HCH in 94.7% of the samples at mean 0.108 mg/kg. To show if organochlorine pesticide levels in monitored female's adipose tissues are age dependant, the group was divided in three ages ranges (13-26, 26-57 and 57-96 years). The mean and median levels of all organochlorine pesticides increase significantly ( p < 0.05) from the first to second and from the first to third group. At the same time, the increase of mean and medians levels from the second to third group were not statistically significant ( p > 0.05). The present results compared to previous ones from 2008 indicates an increase in the concentrations during the 2010 study, but only the differences for pp'DDE and op'DDT were statistically significant. The 2010 group of females was older compared to the 2008 group. The presence of organochlorine pesticide residues is still observed, indicating uniform and permanent exposure to the pesticides by Puebla inhabitants. [ABSTRACT FROM AUTHOR]

The objective of the present study was to monitor the levels of organochlorine pesticides HCB, α- β-γ-HCH, pp′DDE, op′DDT and pp′DDT in 150 adipose tissue samples of Veracruz, Mexico inhabitants. In analyzed samples, the following pesticides were detected: p,p'-DDE in 100% of the samples at mean 1.643 mg/kg; p,p'-DDT in 99.3.% of the samples at mean 0.227 mg/kg; β-HCH in 97.3% of the samples at mean 0.063 mg/kg; and op′DDT in 93.3% of the samples at mean 0.022 mg/kg. Comparing mean, median and geometric mean concentrations of organochlorine pesticides shows a decrease in values from mean to median and to geometric mean which points out a prevalence of lower concentrations among the total samples and the existence of occasional cases of extreme exposure expressed in range values. The pooled samples divided according to sex, showed only significant differences of pp′DDE median concentrations between sexes. The other organochlorine pesticides indicated no statistical differences between sexes, including the pp′DDE/ pp′DDT ratio. The samples grouped according to age, showed that the third tertile was more contaminated for both sexes, indicating age as a positively associated factor with organochlorine pesticide levels in adipose tissue of Veracruz inhabitants. Comparing organochlorine pesticide levels between 2008 and 2010 years, a decreased tendency for β-HCH, pp′DDE, Σ-DDT and pp′DDE/ pp′DDT ratio levels was observed. [ABSTRACT FROM AUTHOR]

The common snook, Centropomus undecimalis, and the locally called chucumite, Centropomus parallelus, occur naturally in the Gulf of Mexico. They are considered high value species and are regularly exploited in coastal fisheries, particularly in the state of Veracruz (Mexico). In order to study their growth in fresh-water artisanal earthen ponds, fingerlings of about 5.5 cm standard length of both species were captured in Alvarado Lagoon (Veracruz) and stocked in three 25 × 10 × 1.20 m ponds at densities of 4:1, 1:1 and 3:2 (chucumite:snook). Tilapia (Oreochromis niloticus) broodstocks were stocked at the same time to supply live food for the snook and chucumite. During the 14-month experimental period, the absolute growth rates in length and weight were recorded, obtaining maximum values of 26.43 ± 0.135 cm and 265.3 ± 0.623 g for C. undecimalis and of 12.0 ± 0.105 cm and 55.1 ± 0.191 g for C. parallelus; the daily growth rate was 0.062 cm for the former and 0.028 cm for the latter. The length-weight relationship estimated (W = aLb) was 3.01 for C. undecimalis and 2.96 for C. parallelus, presenting isometric growth. The fresh-water culture conditions were monitored throughout the experiment, including temperature (26-34°C), dissolved oxygen (4.1-6.9 mg L-1) and pH (6.9-7.5). The culture conditions used did not have any negative effect on growth, since the lengths and weights attained are within the mean values reported for both species. [ABSTRACT FROM AUTHOR]

We evaluated the combined effects of food (0.5 × 106, 1.0 × 106 and 2.0 × 106 cells ml−1 of Chlorella vulgaris) and temperature (15, 20 and 25 °C) on life history variables of B. havanaensis. Regardless of Chlorella density there was a steep fall in the survivorship of B. havanaensis at 25 °C. Both food level and temperature affected the fecundity of B. havanaensis. At any given food level, rotifers cultured at 15 °C showed extended but low offspring production. At 25 °C, offspring production was elevated, the duration of egg laying reduced and the fecundity was higher during the latter part of the reproductive period. The effect of food level was generally additive, at any given temperature, and higher densities of Chlorella resulted in higher offspring production. Average lifespan, life expectancy at birth and generation time were 2–3 times longer at 15 °C than at 25 °C. At 20 °C, these remained at intermediate levels. The shortest generation time (about 4 days) was observed at 25 °C. Gross and net reproductive rates and the rate of population increase ( r) increased with increasing temperature and generally, at any given temperature, higher algal food levels contributed to higher values in these variables. The r varied from 0.11 to 0.66. The survival patterns and lower rates of reproduction at 15 °C suggest that the winter temperatures (10–15 °C) prevailing in many waterbodies in Mexico City allow this species to sustain throughout the year under natural conditions. [ABSTRACT FROM AUTHOR]

The article underscores the first reported records of the leopard cusk-eel Lepophidium pardale (Ophidioidei: Ophidiidae) off the west coast of Baja California Sur, México. It states that the family Ophidiidae contains 48 genera and 222 species, distributed in tropical and temperate waters of the Atlantic, Pacific and Indian oceans. Relative to this, during the demersal trawl surveys along the west coast of the State of Baja California Sur from October 2004 to March 2006, 46 specimens of the leopard cusk-eel were captured. The largest concentrations of this fish were found between Bahia Magdalena and the coast of Todos Santos B. C. S. Mexico.

The growing body of evidence linking intergenerational education and late-life cognitive decline is almost exclusively from high-income countries, despite rapid intergenerational changes in education in low- and middle-income countries (LMICs). We used data from the Mexican Health and Aging Study (n = 8,822), a cohort study of Mexican adults aged ≥50 years (2001-2018), to evaluate whether parental education (none vs. any formal schooling), one's own education (less than primary school vs. completion of primary school), or an adult child's education (less than high school vs. completion of high school) was associated with verbal memory z scores. We used linear mixed models with inverse probability of attrition weights. Educational attainment in all 3 generations was associated with baseline verbal memory scores, independent of the prior generation's education. Lower parental (β = -0.005, 95% confidence interval: -0.009, -0.002) and respondent (β = -0.013, 95% confidence interval: -0.017, -0.010) educational level were associated with faster decline in delayed (but not immediate) verbal memory z scores. Associations between adult child's education and respondent's verbal memory decline varied by exposure specification. The educational attainment of parents and adult children may influence the cognitive aging of middle-aged and older adults in LMICs. These results have important implications given recent structural shifts in educational attainment in many LMICs., (© The Author(s) 2023. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background/objectives: Several longitudinal studies in high-income countries suggest that depression increases stroke risk. However, few prior studies have evaluated this association in low- and middle-income countries (LMICs), where rapidly aging populations may have markedly different vascular risk profiles., Design: Prospective cohort study., Setting: The Mexican Health and Aging Study is a national population-based study of older adults in Mexico., Participants: A total of 10,693 Mexican adults aged 50 and older enrolled in 2001 with no history of prior stroke., Measurements: Depressive symptoms were assessed with a modified 9-item Centers for Epidemiologic Studies Depression Scale (elevated depressive symptom cutoff ≥5) in 2001 and 2003. We evaluated associations between baseline and short-term (2-year) changes in elevated depressive symptoms (categorized as stable low, recently remitted, recent-onset, or stable high symptoms) with incident self-reported or next-of-kin reported doctor-diagnosed stroke through 2015 using Cox proportional hazards models and sensitivity analyses applying inverse probability weights., Results: Over an average follow-up of 11.4 years (standard deviation = 4.2), 10,693 respondents reported 546 incident strokes. Individuals with elevated baseline depressive symptoms experienced a moderately higher hazard of incident stroke (hazard ratio [HR] = 1.13; 95% confidence interval [CI] = .95-1.36) compared with those without elevated baseline depressive symptoms. In analyses of short-term changes in elevated depressive symptoms (n = 8,808; 414 incident stokes), participants with recent-onset (HR = 1.38; 95% CI = 1.06-1.81) or stable high (HR = 1.42; 95% CI = 1.10-1.84) elevated depressive symptoms had a greater hazard of incident stroke compared to those with stable low/no depressive symptoms, whereas recently remitted (HR = 1.01; 95% CI = .74-1.37) symptoms was not associated with stroke hazard., Conclusion: Strategies to reduce depressive symptoms merit evaluation as approaches to prevent stroke in middle-income countries. Findings are similar to those in high-income countries but should be replicated in other LMICs., (© 2020 The American Geriatrics Society.)

Background: Our objective was to establish a sustainable educational partnership and clinical exchange between the trauma services at Vancouver General Hospital (VGH) and the Mexican Red Cross hospital in Mexico City (Hospital Central de la Cruz Roja [HCCR] Polanco)., Methods: In 2017, a general surgery resident in postgraduate year 4 travelled from VGH to HCCR Polanco for the initial exchange, followed by a trauma fellow. The surgical case volumes in a month at VGH and a month at HCCR Polanco were compared. At the end of the exchange, a 36-item Likert style questionnaire was administered to the Mexican surgeons and residents who interacted with the Canadian resident and fellow during the exchange., Results: The most commonly performed procedures on the VGH acute care surgery service were laparoscopic cholecystectomy (35%) and laparoscopic appendectomy (17%). The most commonly performed procedures on the VGH trauma service were chest tube insertions (24%) and tracheostomies (24%). The most commonly performed procedures at HCCR Polanco were surgery for penetrating abdominal trauma (19%) and extremity trauma (13%). The survey results indicated that the costs of travel and accommodation were obstacles to future exchanges. All survey respondents wanted to continue collaborating with Canadians on clinical and research endeavours, felt that hosting Canadian residents was a valuable experience and felt that visiting VGH would also be valuable., Conclusion: Canadian surgical trainees gained valuable exposure to operative trauma during the exchange. The mix of operations performed at VGH and HCCR Polanco was vastly different; therefore, the exchange broadened the trainees' surgical experience. There was a unanimously positive response to the exchange among the Mexican survey respondents. This exchange is part of a long-term collaboration between our surgical centres., Competing Interests: None declared., (© 2020 Joule Inc. or its licensors.)

This investigation uses case studies and comparative analysis to review and analyze aging policy in Argentina, Chile, Costa Rica, and Mexico and uncovers similarities and relevant trends in the substance of historical and current aging policy across countries. Initial charity-based approaches to poverty and illness have been gradually replaced by a rights-based approach considering broader notions of well-being, and recent reforms emphasize the need for national, intersectoral, evidence-based policy. The results of this study have implications for understanding aging policy in Latin America from a welfare regime and policy makers' perspective, identifying priorities for intervention and informing policy reforms in developing countries worldwide.

Background: Mexico recently enacted drug policy reform to decriminalize possession of small amounts of illicit drugs and mandated that police refer identified substance users to drug treatment. However, the economic implications of drug treatment expansion are uncertain. We estimated the costs of opioid substitution therapy (OST) provision in Tijuana, Mexico, where opioid use and HIV are major public health concerns., Methods: We adopted an economic health care provider perspective and applied an ingredients-based micro-costing approach to quantify the average monthly cost of OST (methadone maintenance) provision at two providers (one private and one public) in Tijuana, Mexico. Costs were divided by type of input (capital, recurrent personnel and non-personnel). We defined "delivery cost" as all costs except for the methadone and compared total cost by type of methadone (powdered form or capsule). Cost data were obtained from interviews with senior staff and review of expenditure reports. Service provision data were obtained from activity logs and senior staff interviews. Outcomes were cost per OST contact and cost per person month of OST. We additionally collected information on patient charges for OST provision from published rates., Results: The total cost per OST contact at the private and public sites was $3.12 and $5.90, respectively, corresponding to $95 and $179 per person month of OST. The costs of methadone delivery per OST contact were similar at both sites ($2.78 private and $3.46 public). However, cost of the methadone itself varied substantially ($0.34 per 80 mg dose [powder] at the private site and $2.44 per dose [capsule] at the public site). Patients were charged $1.93-$2.66 per methadone dose., Conclusions: The cost of OST provision in Mexico is consistent with other upper-middle income settings. However, evidenced-based (OST) drug treatment facilities in Mexico are still unaffordable to most people who inject drugs.

Burning the sugar cane field before harvesting has a negative impact on both air and human health, however this issue had not been explored in Mexico. The objective of this work was to determine the chromosomal damage in workers from sugar cane burning fields in Sinaloa, México. To this purpose, we analyzed 1000 cells of buccal exfoliated epithelia from 60 exposed workers and 60 non-exposed controls to determine micronucleus frequencies and other nuclear abnormalities. The results indicated significant higher values of micronucleus and nuclear abnormalities such as binucleate cells, pyknosis, karyolysis, chromatin condensation and nuclear buds frequencies in the exposed subjects compared to those that were not exposed. Our data indicates that sugar cane burning, that generates polycyclic aromatic hydrocarbons, represents a genotoxic risk for workers in this important sugar cane producing area in Mexico., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Background: Gestational diabetes (GD) is third in frequency according to the American Diabetes Association (ADA) and it affects 7% of pregnancies in Mexico, it is related with greater morbidity and mortality. An early diagnosis can avoid pregnancy problems, however the detection of these cases depends on the presence risk factors. Our objective was to know which are the risk factors more frequent for identifiying GD., Methods: Transverse, descriptive study at an endocrinology service of a Gynecology-Pediatrics Hospital. All case records from patients with GD were reviewed with special attention to risk factors. Pregnancy and previous products morbidity history were reviewed as well., Results: 166 patient's files were analyzed aged from 21 to 46, 59% corresponded to > 25 years, 29% with first pregnancy, of these 26% had history of macro products, and 42% were diagnosed in the first half of the pregnancy., Conclusions: The main risk factors related with GD were the age > 25 years and the direct antecedent of DG.

Objective: To determine the prevalence of excessive daytime somnolence (EDS) in a sample of residents from Mexico City., Methods: A cross-sectional survey was done using a randomized telephone survey. A structured questionnaire (including demographic and clinical data) and Epworth Sleepiness Scale, a valid and reliable instrument for the detection of EDS, were administered., Results: A total sample of 200 subjects was obtained, with a mean age of 37 +/- 16.24 years. EDS was found in 31.5% of the subjects; 12.5% considered that EDS interfered in a significant way with daily activities, and 9% with work related abilities. Subjects with EDS were older, came from lower socio-economic status, and had a significantly higher body mass index., Discussion: Our results indicate that EDS is more frequent in Mexico City residents than in other populations. Notwithstanding, the association between EDS with advanced age, lower socio-economic status and high body mass index requires further investigation.

Improving quality of life is the most important goal for patients with epilepsy. To recognize the factors associated with quality of life in patients with epilepsy in Mexico, we performed a cross-sectional survey using the Quality of Life in Epilepsy 31 (QOLIE-31) inventory to assess the quality of life of 401 adult patients with epilepsy at the National Institute of Neurology and Neurosurgery of Mexico. Clinical and demographical data were collected. Multiple regression was used to determine which factors affected quality of life in our patients. The variables that most strongly predicted a lower QOLIE-31 total score after multiple regression were sleep disorders (P<0.001), socioeconomic status (P<0.001), female gender (P=0.002), and high seizure frequency (P=0.001). In our study, neither depression nor time of evolution of epilepsy had significant influence on QOLIE-31 scores.

Objective: To determine the prevalence of gestational diabetes (GD) in a Mexican-U.S. border population and to observe the response of such a population to a 100 gram challenge of glucose., Research Design and Methods: The sample was a cross section of 519 pregnant women accesing different health institutions in Juarez, Mexico, with 24-36 weeks of gestation. An oral glucose tolerance test (OGTT) with a 100 gram challenge of glucose was done on all. Results were interpreted according to the diagnostic criteria of O'Sullivan and Mahan. Information on family history of diabetes, obstetric history, height and weight was obtained., Results: A total of 20.4% of the patients examined had some kind of glucose intolerance 11% with GD and 9.4% with one abnormal value during the glucose tolerance test. The patients with GD tended to be older, had higher gravidity, lower height, higher weight and reported frequently a family history of diabetes. The patients with one abnormal value were similar to those with GD in weight and number of pregnancies, and were comparable to the group with normal glucose tolerance test in height and family history of diabetes., Conclusions: We found a high prevalence of GD and of one abnormal value during the OGTT in a Mexican population. The recommendations for screening for GD must be consistently implemented in pregnant women of Mexican ancestry.