Mexican Institute of Social Security IMSS

Zacatecas, Mexico

Mexican Institute of Social Security IMSS

Zacatecas, Mexico
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Velazquez F.R.,Mexican Institute of Social Security IMSS | Colindres R.E.,Glaxosmithkline | Grajales C.,Coordination of Epidemiology | Hernandez M.T.,Mexican Institute of Social Security IMSS | And 7 more authors.
Pediatric Infectious Disease Journal | Year: 2012

Background: Mexico initiated mass vaccination with the attenuated human rotavirus vaccine (Rotarix) in 2006. This postlicensure study aimed to assess any potential temporal association between vaccination and intussusception in Mexican infants. Methods: Prospective, active surveillance for intussusception among infants aged less than 1 year was conducted in 221 hospitals across Mexico from the Mexican Institute of Social Security between January 2008 and October 2010. The temporal association between vaccination and intussusception was assessed by self-controlled case-series analysis. Results: Of the 753 episodes of intussusception reported in 750 infants, 701 were in vaccinated infants (34.5% post-dose 1, 65.5% post-dose 2). The relative incidence of intussusception within 31 days of vaccination was 1.75 (95.5% confidence interval [CI]: 1.24-2.48; P = 0.001) post-dose 1 and 1.06 (95.5% CI: 0.75-1.48; P = 0.75) post-dose 2. The relative incidence of intussusception within 7 days of vaccination was 6.49 post-dose 1 (95.5% CI: 4.17-10.09; P < 0.001) and 1.29 post-dose 2 (95.5% CI: 0.80-2.11; P = 0.29). Clustering of intussusception within 7 days of vaccination was observed post-dose 1. An attributable risk of 3 to 4 additional cases of intussusception per 100,000 vaccinated infants was estimated. Conclusion: This is the largest surveillance study for intussusception after rotavirus vaccination to date. A temporal increase in the risk for intussusception was seen within 7 days of administration of the first vaccine dose. It is still uncertain whether rotavirus vaccination has any impact on the overall incidence of intussusception. This finding has to be put in perspective with the well-documented substantial benefits of rotavirus vaccination. © 2012 by Lippincott Williams ∧ Wilkins.

Cervantes-Villagrana A.R.,Mexican Institute of Social Security IMSS | Cervantes-Villagrana A.R.,Autonomous University of San Luis Potosi | Hernandez-Pando R.,National Institute of Medical science and Nutrition Salvador Zubiran | Biragyn A.,U.S. National Institute on Aging | And 7 more authors.
Vaccine | Year: 2013

The World Health Organization (WHO) has estimated that there are about 8 million new cases annually of active Tuberculosis (TB). Despite its irregular effectiveness (0-89%), the Bacillus Calmette-Guérin) BCG is the only vaccine available worldwide for prevention of TB; thus, the design is important of novel and more efficient vaccination strategies. Considering that β-defensin-2 is an antimicrobial peptide that induces dendritic cell maturation through the TLR-4 receptor and that both ESAT-6 and Ag85B are immunodominant mycobacterial antigens and efficient activators of the protective immune response, we constructed two DNA vaccines by the fusion of the gene encoding β-defensin-2 and antigens ESAT6 (pDE) and 85B (pDA). After confirming efficient local antigen expression that induced high and stable Interferon gamma (IFN-γ) production in intramuscular (i.m.) vaccinated Balb/c mice, groups of mice were vaccinated with DNA vaccines in a prime-boost regimen with BCG and with BCG alone, and 2 months later were challenged with the mild virulence reference strain H37Rv and the highly virulent clinical isolate LAM 5186. The level of protection was evaluated by survival, lung bacilli burdens, and extension of tissue damage (pneumonia). Vaccination with both DNA vaccines showed similar protection to that of BCG. After the challenge with the highly virulent Mycobacterium tuberculosis strain, animals that were prime-boosted with BCG and then boosted with both DNA vaccines showed significant higher survival and less tissue damage than mice vaccinated only with BCG. These results suggest that improvement of BCG vaccination, such as the prime-boost DNA vaccine, represents a more efficient vaccination scheme against TB. © 2012 Elsevier Ltd.

Rivas-Santiago B.,Mexican Institute of Social Security IMSS | Cervantes-Villagrana A.R.,Autonomous University of Zacatecas
Scandinavian Journal of Infectious Diseases | Year: 2014

It is estimated that there are approximately eight million new cases of active tuberculosis (TB) worldwide annually. There is only 1 vaccine available for prevention: bacillus Calmette-Guérin (BCG). This has variable efficacy and is only protective for certain extrapulmonary TB cases in children, therefore new strategies for the creation of novel vaccines have emerged. One of the promising approaches is the DNA vaccine, used as a direct vaccination or as a prime-boost vaccine. This review describes the experimental data obtained during the design of DNA vaccines for TB. © 2014 Informa Healthcare.

Moran C.,Direction of Health Research and Training | Moran C.,Mexican Institute of Social Security IMSS | Tena G.,Direction of Health Research and Training | Moran S.,Mexican Institute of Social Security IMSS | And 3 more authors.
Gynecologic and Obstetric Investigation | Year: 2010

Background/Aims: Polycystic ovary syndrome (PCOS) has been found to affect 4-8% of women of reproductive age; however, in Mexican-Americans a prevalence of 12.8% has been reported. This study determines the prevalence of PCOS in a sample of Mexican women. Methods: This prospective cross-sectional study included 150 female Mexican volunteers aged 20-45 years. Menstrual cycles were recorded and hirsutism was graded. Pelvic ultrasound was performed and androgen levels were measured. PCOS was diagnosed by hyperandrogenism and/or hyperandrogenemia, and oligo-ovulation (NIH 1990 criteria), and also by 2 of 3 findings: oligo-ovulation, clinical and/or biochemical hyperandrogenism and polycystic ovaries (PCO) (Rotterdam 2003 criteria), excluding other disorders. Results: Nine of the 150 women were diagnosed with PCOS, a prevalence of 6.0% (95% CI: 1.9-10.1%), according to NIH criteria. The ultrasound morphology added one patient to give ten PCOS patients, a prevalence of 6.6% (95% CI: 2.3-10.9%) according to Rotterdam criteria. All PCOS patients presented oligo-ovulation, 9 had hirsutism and 7 of them had acne. Eight of the 10 PCOS patients had morphologic characteristics of PCO. Conclusion: The prevalence of PCOS in Mexican women is approximately 6.0%, similar to other populations, but lower than 12.8% reported in Mexican-American women. © 2010 S. Karger AG, Base.

Rivas-Santiago C.E.,Rutgers University | Hernandez-Pando R.,National Institute of Medical science and Nutrition Salvador Zubiran | Rivas-Santiago B.,Mexican Institute of Social Security IMSS
Immunotherapy | Year: 2013

TB is an infectious disease that still has an enormous impact on public health worldwide. With the continuous increasing epidemic of multidrug-resistant TB, new drugs and vaccines are urgently needed. In the last decade there has been a broad advance in the knowledge of innate immunity in TB. Together with the growing research regarding immunomodulators, new promising insights have been developed that can contribute in the control of TB. This is the case of antimicrobial peptides, which can be potential therapeutic or adjuvant agents. The current high cost of antimicrobial peptide synthesis may be a current deterrent for treatment; antimicrobial peptide-inducers can be an alternative for low-cost treatment and/or adjuvants. © 2013 Future Medicine Ltd.

Gutierrez J.P.,National Health Research Institute | Garcia-Saiso S.,Ministryof Health | Dolci G.F.,Mexican Institute of Social Security IMSS | Avila M.H.,National Institute of Public Health INSP
BMC Health Services Research | Year: 2014

Background: Effective access measures are intended to reflect progress toward universal health coverage. This study proposes an operative approach to measuring effective access: in addition to the lack of financial protection, the willingness to make out-of-pocket payments for health care signifies a lack of effective access to pre-paid services. Methods. Using data from a nationally representative health survey in Mexico, effective access at the individual level was determined by combining financial protection and effective utilization of pre-paid health services as required. The measure of effective access was estimated overall, by sex, by socioeconomic level, and by federal state for 2006 and 2012. Results: In 2012, 48.49% of the Mexican population had no effective access to health services. Though this represents an improvement since 2006, when 65.9% lacked effective access, it still constitutes a major challenge for the health system. Effective access in Mexico presents significant heterogeneity in terms of federal state and socioeconomic level. Conclusions: Measuring effective access will contribute to better target strategies toward universal health coverage. The analysis presented here highlights a need to improve quality, availability, and opportuneness (location and time) of health services provision in Mexico. © 2014 Gutiérrez et al.; licensee BioMed Central Ltd.

Serrano-Escobedo C.J.,Mexican Institute of Social Security IMSS | Enciso-Moreno J.A.,Mexican Institute of Social Security IMSS | Monarrez-Espino J.,Karolinska Institutet
Archives of Medical Research | Year: 2013

Background and Aims: We undertook this study to compare the performance of tuberculin skin test (TST) and QuantiFERON-TB-Gold In-tube assay (QFT-IT) to identify latent TB infection (LTBI) among close contacts of pulmonary TB cases. Methods: A cross-sectional study was conducted in north central Mexico. Thirty nine TB index cases diagnosed between 2008 and 2010 and 123 corresponding close contacts were interviewed regarding their exposure time to the index case prior to TB diagnosis and relevant sociodemographic factors. TST (induration ≥5 and ≥10 mm) and QFT-IT (≥0.35 IU/mL) were tested to determine LTBI status. Kappa coefficients were used to assess the agreement between TST and QFT-IT. Multivariate logistic regression modeling using TST and QFT-IT as dependent variables, and cumulative exposure time and sociodemographic variables associated with LTBI were used as independent variables. Results: LTBI prevalence in adult contacts was 53.6 and 34.1% when TST cut-offs were set at ≥5 mm and ≥10, respectively, and 41.4% according to QFT-IT. Agreement between TST and QFT-IT was 73.1 and 74.8%, and kappa coefficients 0.47 and 0.46, for TST ≥5 and ≥10 mm, respectively, although these were higher when data were stratified by cumulative exposure, reaching 84.9% and 0.70 for TST ≥5 mm if exposure was ≥500 h/month. None of the predictive variables analyzed for LTBI using multivariate regression was significantly associated. Conclusions: TST ≥5 mm appears to be a useful test to identify LTBI among closely exposed contacts in this geographic setting. © 2013 IMSS.

Corrales-Garcia L.,National Autonomous University of Mexico | Corrales-Garcia L.,University of Antioquia | Ortiz E.,National Autonomous University of Mexico | Castaneda-Delgado J.,Mexican Institute of Social Security IMSS | And 2 more authors.
Protein Expression and Purification | Year: 2013

Five variants of human β-defensins (HBDs) were expressed in Escherichia coli using two vector systems (pET28a(+) and pQE30) with inducible expression by IPTG. The last vector has not been previously reported as an expression system for HBDs. The recombinant peptides were different in their lengths and overall charge. The HBDs were expressed as soluble or insoluble proteins depending on the expression system used, and the final protein yields ranged from 0.5 to 1.6 mg of peptide/g of wet weight cells, with purities higher than 90%. The recombinant HBDs demonstrated a direct correlation between antimicrobial activity and the number of basic charged residues; that is, their antimicrobial activity was as follows: HBD3-M-HBD2 > HBD3 = HBD3-M = HB2-KLK > HBD2 when assayed against E. coli, Staphylococcus aureus and Pseudomonas aeruginosa. Interestingly, HBD2 had the best antimicrobial activity against the Mycobacterium tuberculosis strain H37Rv (1.5 μM) and the heterologous tandem peptide, HBD3-M-HBD2, had the best minimal inhibitory concentration (MIC) value (2.7 μM) against a multidrug resistance strain (MDR) of M. tuberculosis, demonstrating the feasibility of the use of HBDs against pathogenic M. tuberculosis reported to be resistant to commercial antibiotics. © 2013 Elsevier Inc. All rights reserved.

Nevarez-Sida A.,Mexican Institute of Social Security IMSS | Constantino-Casas P.,Mexican Institute of Social Security IMSS | Castro-Rios A.,Mexican Institute of Social Security IMSS
BMC Public Health | Year: 2012

Background: Consumption of illegal drugs is a public health problem in Mexico, and the prison population is a vulnerable group with higher rates of prevalence than in the general population. The objective of this study was to determine the main socioeconomic variables associated with drug consumption in the prison population. Methods. Utilizing data from the Second Incarcerated Population Survey carried out by the Centre of Research and Teaching of Economics (CIDE) in Mexico, a logistic model in two stages was developed. The first stage analyzed the determinants of habitual drug consumption by prisoners (prior to admittance into prisons), while the second stage of the model addressed drug consumption within prisons. Results: Prevalence of drug consumption previous to incarceration was 28.5%, although once people were imprisoned this figure dropped to 7.4%. The characteristics that most heavily influenced against the possibility of habitual drug consumption prior to admittance to prison were: preparatory school or higher, being employed and having children; while the variables associated negatively were: male gender, childhood home shared with adults who consumed illegal drugs; abandoning childhood home; and having previous prison sentences. Once in prison, the negative conditions in there are associated with drug consumption. Conclusions: Work and study during incarceration, in addition to being instruments for rehabilitation, seem to exert an important positive association against drug consumption. However, this correlation seems to be minimized in the face of negative conditions of the penal institution; thus, public policies are necessary to improve the prisoner's environment. © 2012 Nevarez-Sida et al; BioMed Central Ltd.

Varqa A.N.,Mexican Institute of Social Security IMSS
ecancermedicalscience | Year: 2014

Ovarian cancer is a disease laden with paradigms, and it is a serious health problem. It is important to know its natural history, as it is multifactorial in origin, and also to understand its behaviour given its risk factors which can lead to death from metastasis in patients. It continues to be a challenge for oncologists. An analytical literature review was performed to update the latest concepts of its origin, evolution, risk factors, pre-clinical horizon, and its clinical manifestations; until the death of the patient. © the authors; licensee ecancermedicalscience.

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