Iron, cadmium, and chromium in seagrass (Thalassia testudinum) from a coastal nature reserve in karstic Yucatán.

The management of protected areas in karstic regions is a challenge because flooded cave systems form there and provide underground hydrological conducts that may link different zones. As a consequence, affectations to the protected areas can possibly occur as a consequence of human activities in remote areas and may therefore pass undetected. Thus, the monitoring of possible contaminants in these regions is becoming imperative.

[The 2008 Nobel Prizes in medicine and physiology].

For the last century, the Nobel Prize in physiology and medicine has been awarded worldwide to significant discoveries. The prize allows the dissemination of information on the achievements of recipients, promotes understanding of scientific knowledge among the public and attracts young students to biomedical research. This paper briefly describes the prizes granted to the fields of physiology and medicine, emphasizing those that related to development of vaccines.

Using national health weeks to deliver deworming to children: lessons from Mexico.

Mexico established national health weeks (NHWs) in the early 1980s to promote childhood vaccinations. Because of the cumulative worldwide peer-reviewed scientific evidence, the recommendations of the World Health Organization and other international organisations, the political will of the Mexican government and the infrastructure provided by the NHWs, deworming was added to the NHWs in 1993. In addition to the Ministry of Health, several other government organisations participated in administering the deworming component.

[Improvement of child survival in Mexico: the diagonal approach].

Public health interventions aimed at children in Mexico have placed the country among the seven countries on track to achieve the goal of child mortality reduction by 2015. We analysed census data, mortality registries, the nominal registry of children, national nutrition surveys, and explored temporal association and biological plausibility to explain the reduction of child, infant, and neonatal mortality rates. During the past 25 years, child mortality rates declined from 64 to 23 per 1000 livebirths.

Improvement of child survival in Mexico: the diagonal approach.

Public health interventions aimed at children in Mexico have placed the country among the seven countries on track to achieve the goal of child mortality reduction by 2015. We analysed census data, mortality registries, the nominal registry of children, national nutrition surveys, and explored temporal association and biological plausibility to explain the reduction of child, infant, and neonatal mortality rates. During the past 25 years, child mortality rates declined from 64 to 23 per 1000 livebirths.

Aerosol measles vaccination in macaques: preclinical studies of immune responses and safety.

The comparative efficacy and safety of measles vaccination via the aerosol route versus subcutaneous injection has not been fully resolved. We vaccinated cynomolgus monkeys (Macaca fascicularis) with the live-attenuated Edmonston-Zagreb measles virus (MV) vaccine and compared different routes of administration in the immunocompetent and the immunocompromised host. Immunogenicity and protective efficacy of aerosol vaccination using devices similar to those previously used in humans were comparable to those in animals vaccinated by injection.

Cholera in Mexico: the paradoxical benefits of the last pandemic.

Objectives: To describe the impact of preventive and control measures in Mexico prior to, and during, the cholera epidemic of 1991-2001.

Methods: When cholera appeared in Latin America in January 1991, the Mexican government considered that it represented a national security problem. Therefore, actions were implemented within the health sector (e.

Rifampin and pyrazinamide vs isoniazid for prevention of tuberculosis in HIV-infected persons: an international randomized trial. Terry Beirn Community Programs for Clinical Research on AIDS, the Adult AIDS Clinical Trials Group, the Pan American Health Organization, and the Centers for Disease Control and Prevention Study Group.

Context: Because of problems with adherence, toxicity, and increasing resistance associated with 6- to 12-month isoniazid regimens, an alternative short-course tuberculosis preventive regimen is needed.

Objective: To compare a 2-month regimen of daily rifampin and pyrazinamide with a 12-month regimen of daily isoniazid in preventing tuberculosis in persons with human immunodeficiency virus (HIV) infection.

Design: Randomized, open-label controlled trial conducted from September 1991 to May 1996, with follow-up through October 1997.

Population-based prevalence of symptomatic and asymptomatic astrovirus infection in rural Mayan infants.

Symptomatic and asymptomatic astrovirus infection was prospectively determined in a 3-year birth cohort of Mayan infants. Stool samples from 271 infants and 268 older siblings were tested for astrovirus, adenovirus 40/41, rotavirus and Salmonella, Shigella and Campylobacter species. Concurrent diarrhea, vomiting, fever, or anorexia were noted.

Host and viral factors affecting the decreased immunogenicity of Sabin type 3 vaccine after administration of trivalent oral polio vaccine to rural Mayan children.

Factors affecting immunogenicity of the first 2 doses of oral poliovirus vaccine (OPV) among unimmunized Mayan infants were prospectively evaluated. The relative impact of multiple variables, including mass or routine vaccination, concurrent enteric bacterial (salmonella, shigella, and campylobacter) and viral (adenovirus 40/41, astrovirus, nonpolio enteroviruses, and rotavirus) infections, interference among Sabin vaccine viruses, and preexisting poliovirus antibodies were studied. Sera were available from 181 infants after 2 OPV doses.

[An operative primary health care services model including physicians and technicians].

The operative Model of Primary Health Care, was developed to offer health services to a population living under conditions of extreme poverty in the municipality of Chimalhuacán, State of México. This article describes the theorical framework, organization and operationalization of an innovative model, changing the current paradigm of clinical practice to include allied health personnel with and especial training. At the core of the model is the Basic Unit of Primary Care that includes one physician and five allied health technicians for each 15,000 habitants.

[Antibiotic resistance pattern of 24, 526 strains of Vibrio cholerae O1 isolated in Mexico from 1991 to 1993].

Profile of antimicrobial resistance by Kirby-Bauer method was performed on 24526 Vibrio cholerae O1 strains isolated in México (1991-1993) from fecal swabs in cholera cases and from asymptomatic carriers. Minimal inhibitory concentration (MIC) tests for tetracycline (Te) and doxycycline (D) were done on selected strains. Single antibiotic discs were used at concentrations of: Te, 30 micrograms; D, 30 micrograms; erythromycin (E), 15 micrograms; chloramphenicol (CM), 30 micrograms; ampicillin (AM), 10 micrograms; trimethoprim-sulfamethoxazole (SXT) 1.

[Seroepidemiology of brucellosis in Mexico].

Brucellosis is an important and widely distributed zoonosis in Mexican cattle which also affects an unknown proportion of the human population. This report presents the brucellosis antibody levels registered in the National Seroepidemiology Survey (NAS) in sera obtained from 66,982 healthy persons from one to 98 years of age and determined by the test of plaque microagglutination. Seroprevalences by states ranged from 0.

[Seroepidemiology of toxoplasmosis in Mexico].

This article presents to the results of the National Seroepidemiology Survey with regard to the prevalence of toxoplasmosis in Mexico. Some theoretical aspects of the disease are discussed, and the prevalences found in earlier reports are presented. The study measured 29,279 blood samples from persons in all 32 states of Mexico, for both sexes, all ages, and socio-economic groups.

[Seroepidemiology of Chagas disease in Mexico].

The lack of information about Chagas disease in Mexico, as well as the controversy concerning its importance, was the basis for the seroprevalence study of Trypanosoma cruzi in the National Seroepidemiology Survey (NSS). This information was representative of the national situation with regard to disease prevalences and other factors related to the nation's health. Unfortunately the NSS was not a very good information source for the study of trypanosomiasis americana, because its coverage in the disperse rural areas was poor.

[Seroepidemiology of whooping cough in Mexico].

This paper presents the results from a serological survey developed in Mexico during 1987 in order to estimate the prevalence of anti Bordetella pertussis antibodies. Agglutinins were measured in 25,666 samples taken from children one to 15 years old living throughout the country. In each case survey covered some data about social and demographic variables such as socioeconomic stratum, number of DPT vaccine doses received and urban or rural settlement, among others.

[Seroepidemiology of measles in Mexico].

Measles is an illness of universal distribution and great social impact. According to the WHO, the annual deaths due to this disease amount to more than a million children in the world. The objectives of this paper are to estimate the seroprevalence of titer of antibodies to measles in the population of 12 to 59 months of age in Mexico and identify the determinants of the immunity state.

Immunization of six-month-old infants with different doses of Edmonston-Zagreb and Schwarz measles vaccines.

Because measles causes an estimated 2 million deaths per year among children in developing countries, including a substantial proportion of infants less than nine months old--the age at which vaccination is recommended--there has been interest in using different strains of vaccine and higher doses to achieve immunization of younger infants. We conducted a randomized trial of three different doses of Edmonston-Zagreb and of Schwarz measles vaccines in infants to evaluate the effect of the strain and dose of vaccine on the serologic response and acute adverse reactions to vaccination. Six-month-old infants received a standard, medium, or high dose of one of the vaccines, and nine-month-old infants received a standard dose.

The epidemiology of HIV transmission among paid plasma donors, Mexico City, Mexico.

Screening of blood product donations for antibody to HIV began in Mexico in May 1986. From June to October 1986, the HIV cumulative seroprevalence increased from 6.3 to 9.

AIDS in Mexico: trends and projections.

The first case of AIDS in Mexico was reported in 1981. Through mid-1988, 1,502 cases had been reported, the incidence of cases having doubled every 7.7 months.