DNA methylation profile of a rural cohort exposed to early-adversity and malnutrition: An exploratory analysis

Barker's hypothesis affirms that undernourishment in early-life induces metabolic reprogramming that compromises organism functions later in life, leading to age-related diseases. We are exposed to environmental and social conditions that impact our life trajectories, leading to ageing phenotypes as we grow. Epigenetic mechanisms constitute the link between both external stimuli and genetic programming. Studies have focused on describing the effect of early adverse events such as trauma, famines, or childhood labor on epigenetic markers in adulthood and the elderly. However, we lack information on epigenetic programming in individuals born in rural communities from underdeveloped countries, exposed to negative influences during fetal and postnatal development, particularly chronic malnutrition. Hence, in this exploratory analysis, we characterize the epigenome of individuals and some parents from Tlaltizapan (a rural community in Mexico originally studied almost 50 years ago) and collect anthropometric data on growth and development, as well on the living conditions of the families. Our results help build a biological hypothesis indicating that most of the epigenetic age measures of the subjects are significantly different among them. Interestingly, the most affected methylated regions correspond to pathways involved in neuronal system development, reproductive behaviour, learning and memory regulation.

Observational pilot study of patients with carpal tunnel syndrome treated with Nucleo CMP Forte™

AIM

Carpal tunnel syndrome (CTS) is a very common entrapment neuropathy characterized by pain and paresthesia in the territory of the median nerve. Although this syndrome has a considerable impact on the patient's quality of life, its medical treatment is far from optimal.

MATERIAL & METHODS

We performed an observational study to evaluate Nucleo CMP Forte^TM in patients with electromyography-confirmed, mild-moderate CTS. Pain was assessed using a visual analog scale, electromyogram and the SF-36.

RESULTS

Pain decreased significantly after 6 months. Quality of life improved significantly in the pain dimensions. No significant differences were observed in electromyographic findings. No adverse events were reported.

CONCLUSIONS

Nucleotides could prove useful for the nonsurgical treatment of CTS. Further studies are necessary to confirm this.

Estudio del comportamiento porcino: una mirada etológica sobre la producción porcina

 El conocimiento del comportamiento permite mejorar el manejo de los animales utilizados en producción y optimizar su bienestar. La disciplina de las ciencias biológicas que aborda este tema es la etología. Basada en la teoría de la evolución, pone énfasis en cuatro tipos de explicaciones, conocidas como las “4 preguntas de Tinbergen”. ¿Son estos cuatro abordajes útiles para la etología aplicada a la producción de porcinos? ¿Las investigaciones en etología pueden aportar a la mejora en las condiciones de crianza? Y, fundamentalmente, ¿son relevantes para el bienestar animal? Algunas prácticas realizadas de manera “intuitiva” o “empírica” hoy pueden ser identificadas como “la ayuda silenciosa” que la etología ha aportado a cada etapa productiva desde el inicio de la utilización de la cría de animales domésticos, particularmente cuando esta comienza a realizarse de manera intensiva. Esta ayuda silenciosa generó un conjunto de saberes específicos que, paradójicamente, no se relacionan con esta disciplina. Proponemos aquí darle voz a esta ayuda, identificando los distintos desarrollos etológicos implicados en la producción porcina.

Prevalence of Sarcopenia in Community-Dwelling Chilean Elders According to an Adapted Version of the European Working Group on Sarcopenia in Older People (EWGSOP) Criteria

BACKGROUND

Sarcopenia is the progressive loss of mass and skeletal muscle strength and has serious consequences on older people's health. The Chilean older population has a high life-expectancy, but the prevalence of functional dependence is also high.

OBJECTIVE

To determine the prevalence of sarcopenia in Chilean older adults and its relationship with age, gender, and body mass index (BMI).

DESIGN

Cross-sectional study.

SETTING

Community.

PARTICIPANTS

1,006 non-disabled, community-dwelling subjects aged 60 years or older living in Santiago.

MEASUREMENTS

Anthropometric measurements, handgrip strength, physical performance tests, and dual-energy-x-ray-absorptiometry (DXA) scan were performed. Sarcopenia was defined using the algorithm of the European Working Group on Sarcopenia in Older People (EWGSOP). Muscle mass was measured with DXA scan; skeletal muscle mass index (SMI) and hand dynamometry were defined with cut-off points obtained for the Chilean population. For a 3m walking speed we used the cut-off point of the EWGSOP definition. Nutritional status and obesity were defined according to World Health Organization standards. Association between sarcopenia and age, gender, BMI and lean/fat mass ratio was estimated by logistic regression models.

RESULTS

The prevalence of sarcopenia was 19.1% (95%CI: 16.8%-21.8%), similar in men and women. There was an increasing trend of sarcopenia by age group and a decreasing trend with nutritional status. After logistic regression, sarcopenia was positively associated with age (OR=1.10; 95%CI:1.06-1.15) and falls (OR=1.83; 95%CI:1.07-3.15) and negatively associated with overweight (OR=0.31; 95%CI:0.16-0.59), obesity (OR=0.02; 95%CI:0.004-0.11), lean mass/fat mass ratio (OR=0.69; 95%CI:0.48-0.9997), knee height (OR=0.78; 95%CI:0.68-0.89) and calf circumference (OR=0.87; 95%CI:0.77-0.97).

CONCLUSIONS

The total prevalence of sarcopenia was 19.1% increasing with age reaching 39.6% in people of 80 or more years of age. A negative association of sarcopenia with overweight, obesity and lean/fat mass ratio was observed. Although the high prevalence of obesity (35.9%), only 2% of obese people were sarcopenic.

Insulin receptor isoforms: an integrated view focused on gestational diabetes mellitus

The human insulin receptor (IR) exists in two isoforms that differ by the absence (IR-A) or the presence (IR-B) of a 12-amino acid segment encoded by exon 11. Both isoforms are functionally distinct regarding their binding affinities and intracellular signalling. However, the underlying mechanisms related to their cellular functions in several tissues are only partially understood. In this review, we summarize the current knowledge in this field regarding the alternative splicing of IR isoform, tissue-specific distribution and signalling both in physiology and disease, with an emphasis on the human placenta in gestational diabetes mellitus (GDM). Furthermore, we discuss the clinical relevance of IR isoforms highlighted by findings that show altered insulin signalling due to differential IR-A and IR-B expression in human placental endothelium in GDM pregnancies. Future research and clinical studies focused on the role of IR isoform signalling might provide novel therapeutic targets for treating GDM to improve the adverse maternal and neonatal outcomes.

Influence of environmental variables on the structure and composition of soil bacterial communities in natural and constructed wetlands

Bacteria are key players in wetland ecosystems, however many essential aspects regarding the ecology of wetland bacterial communities remain unknown. The present study characterizes soil bacterial communities from natural and constructed wetlands through the pyrosequencing of 16S rDNA genes in order to evaluate the influence of wetland variables on bacterial community composition and structure. The results show that the composition of soil bacterial communities was significantly associated with the wetland type (natural or constructed wetland), the type of environment (lagoon, Typha or Salix) and three continuous parameters (SOM, COD and TKN). However, no clear associations were observed with soil pH. Bacterial diversity values were significantly lower in the constructed wetland with the highest inlet nutrient concentrations. The abundances of particular metabolic groups were also related to wetland characteristics.

Characterisation of the soil bacterial community structure and composition of natural and constructed wetlands

In the present study, the pyrosequencing of 16S ribosomal DNA was used to characterise the soil bacterial community composition of a constructed wetland receiving municipal wastewater and a nearby natural wetland. Soil samples were taken from different locations in each wetland (lagoon, zone with T. latifolia, zone with S. atrocinerea). Moreover, the water quality parameters were evaluated (pH, Tª, conductivity, dissolved oxygen, redox potential, nutrients and suspended solids), revealing that the organic matter and nutrient contents were significantly higher in the constructed wetland than in the natural one. In general, the bacterial communities of the natural wetland were more diverse than those of the constructed wetland. The major phylogenic groups of all soils included Proteobacteria, Verrucomicrobia and Chloroflexi, with Proteobacteria being the majority of the community composition. The Verrucomicrobia and Chloroflexi phyla were more abundant in the natural wetland than the constructed wetland; in contrast, the Proteobacteria phylum was more abundant in the constructed wetland than the natural wetland. Beta diversity analyses reveal that the soil bacterial communities in the natural wetland were less dissimilar to each other than to those of the constructed wetland.

Role of equilibrative adenosine transporters and adenosine receptors as modulators of the human placental endothelium in gestational diabetes mellitus

Gestational diabetes mellitus (GDM) is a diseases that alters human placenta macro and microvascular reactivity as a result of endothelial dysfunction. The human placenta is a highly vascularized organ which lacks innervation, so blood flux is governed by locally released vasoactive molecules, including the endogenous nucleoside adenosine and the free radical nitric oxide (NO). Altered adenosine metabolism and uptake by the endothelium leads to increased NO synthesis which then turns-off the expression of genes coding for a family of nucleoside membrane transporters belonging to equilibrative nucleoside transporters, particularly isoforms 1 (hENT1) and 2 (hENT2). This mechanism leads to increased extracellular adenosine and, as a consequence, activation of adenosine receptors to further sustain a tonic activation of NO synthesis. This is a phenomenon that seems operative in the placental macro and microvascular endothelium in GDM. We here summarize the findings available in the literature regarding these mechanisms in the human feto-placental circulation. This phenomenon is altered in the feto-placental vasculature, which could be crucial for understanding GDM deleterious effects in fetal growth and development.

Mortality as an adverse outcome of sarcopenia

Sarcopenia has an important impact in elderly. Recently the European Working Group on Sarcopenia in Older People (EWGSOP) defined sarcopenia as the loss of muscle mass plus low muscle strength or low physical performance. Lack of clinical sounding outcomes (ie external validity), is one of the flaws of this algorithm. The aim of our study was to determine the association of sarcopenia and mortality in a group of Mexican elderly. A total of 345 elderly were recruited in Mexico City, and followed up for three years. The EWGSOP algorithm was integrated by: gait speed, grip strength and calf circumference. Other covariates were assessed in order to test the independent association of sarcopenia with mortality. Of the 345 subjects, 53.3% were women; with a mean age of 78.5 (SD 7) years. During the three year follow-up a total of 43 (12.4%) subjects died. Age, cognition, ADL, IADL, health self-perception, ischemic heart disease and sarcopenia were associated in the bivariate analysis with survival. Negative predictive value for sarcopenia regarding mortality was of 90%. Kaplan-Meier curves along with their respective log-rank test were significant for sarcopenia. The components of the final Cox-regression multivariate model were age, ischemic heart disease, ADL and sarcopenia. Adjusted HR for age was 3.24 (CI 95% 1.55-6.78 p 0.002), IHD 5.07 (CI 95% 1.89-13.59 p 0.001), health self-perception 5.07 (CI 95% 1.9-13.6 p 0.001), ADL 0.75 (CI 95% 0.56-0.99 p 0.048) and sarcopenia 2.39 (CI 95% 1.05-5.43 p 0.037).

Differences of small intestinal bacteria populations in adults and children with/without celiac disease: effect of age, gluten diet, and disease

BACKGROUND

Scientific evidence has revealed microecological changes in the intestinal tract of celiac infants. The objective of this work is the study of bacterial differences in the upper small intestine in both adults (healthy, untreated celiac disease [CD], and CD treated with a gluten-free diet) and children (healthy and untreated CD).

METHODS

Intestinal bacterial communities were identified by 16S rRNA gene sequencing of DNA extracted from duodenal biopsies.

RESULTS

Analysis of the sequences from adults and children showed that this niche was colonized by bacteria affiliated mainly with three phyla: Firmicutes, Proteobacteria, and Bacteroidetes. In total, 89 different genera were identified in adults and 46 in children. Bacterial richness was significantly lower in the children than in the adults. A global principal component analysis of the bacterial communities of both healthy and untreated CD patient groups (including both children and adults) revealed a strong effect of age in principal component 1--clustering all adults and children separately--and a possible effect of the disease in adults with untreated patients clustering separately.

CONCLUSIONS

There are bacterial differences in the upper small intestine between untreated children CD patients and untreated CD adults due to age. There are bacterial differences in the upper small bacteria microbiota between treated and untreated CD adults due to treatment with a gluten-free diet.

Comparative analysis of the composition of bacterial communities from two constructed wetlands for municipal and swine wastewater treatment

This work provides information about bacterial community structure in natural wastewater treatment systems treating different types of wastewater. The diversity and composition of bacterial communities associated with the rhizosphere of Typha latifolia and Salix atrocinerea were studied and compared among two different natural wastewater treatment systems, using the direct sequencing of the 16S ribosomal RNA codifying genes. Phylogenetic affiliations of the bacteria detected allowed us to define the main groups present in these particular ecosystems. Moreover, bacterial community structure was studied through two diversity indices. Ten identified and five non-identified phyla were found in the samples; the phylum Proteobacteria was the predominant group in the four ecosystems. The results showed a bacterial community dominated by beta-proteobacteria and a lower diversity value in the swine wastewater treatment system. The municipal wastewater treatment system presented a high diverse community in both macrophytes (Typha latifolia and Salix atrocinerea), with gamma-proteobacteria and alpha-proteobacteria, respectively, as the most abundant groups.

Anthropometric measurements in the elderly population of Santiago, Chile

OBJECTIVE

There are few studies on anthropometry and nutritional status in large and representative samples of elderly populations in Chile and South America. We describe age and sex differences in weight, height, body mass index, knee height, waist circumference, midarm circumference, triceps skinfold thickness, arm muscle area, and calf circumference in Chilean elderly subjects.

METHODS

This was a population-based, cross-sectional study. A total of 1220 elderly persons (819 women and 411 men; age range, 60-99 y) were recruited in the city of Santiago (Chile) through a probabilistic sampling procedure carried out from October to December 1999.

RESULTS

Men were significantly heavier and taller than women in all age groups, whereas body mass index values were significantly higher in women than in men. All anthropometric variables showed a decrease in average values with aging in men and women. The apparent negative slopes for the decline in average values of body weight with aging was of greater magnitude in women than in men (-0.42 kg/y and -0.54 kg/y in male and female subjects, respectively). However, significant age x sex interaction was detected only for triceps skinfold thickness. In women, quadratic terms for age provided a significantly better fit than did the simple linear model for the association between age and weight, body mass index, waist circumference, triceps skinfold thickness, calf circumference, or midarm circumference.

CONCLUSION

These observations indicated that body weight changes associated with aging might be more severe in Chilean women than in men, probably determining a differential pattern of lean and fat mass loss.

Polymorphisms in candidate genes for type 2 diabetes mellitus in a Mexican population with metabolic syndrome findings

The metabolic or insulin resistance syndrome, characterized by hypertension, dyslipidemia, glucose intolerance and hyperinsulinemia, may have genetic determinants. The insulin gene (INS), insulin receptor gene (INSR) and insulin receptor substrate 1 gene (IRS1) have been proposed as candidate genes. We examined eight polymorphisms in these genes in 163 individuals from Yucatan, Mexico; this population has a high prevalence of obesity, type 2 diabetes mellitus and dyslipidemia. Subjects were evaluated for body mass index (BMI) and blood pressure. Blood samples were collected to determine glucose, insulin, triglycerides and cholesterol levels, as well as for DNA isolation. Restriction fragment length polymorphisms in INS, INSR and IRS1 were identified by polymerase chain reaction and digestion with selected restriction enzymes. Among the eight polymorphisms analyzed, the PstI polymorphism in INS was significantly associated with hypertriglyceridemia and with the presence of at least one abnormality related to the metabolic syndrome (P=0.007 and 0.004, respectively). The MaeIII polymorphism in INS was associated with fasting hyperinsulinemia (P=0.045). In multilocus analyses including both INS polymorphisms, significant associations were seen with hypertriglyceridemia (P=0.006), hypercholesterolemia (P=0.031) and with presence of at least one metabolic abnormality (P=0.009). None of the polymorphisms in INSR or IRS1 was associated with any of these traits. These findings suggest that the insulin gene may be an important determinant of metabolic syndrome, and particularly of dyslipidemia, in this population.

Research trends in mother-child healthcare, 1966-1995

OBJECTIVE

To explore trends in mother-child healthcare (MCHC) research over the past 30 years.

METHODS

Classifications of Medline articles were made at 5-year intervals using Medical Subject Headings (MeSH) as classifiers. Papers were classified in mutually and non-mutually exclusive categories by subject (mother and four age groups of children) and type of research (clinical, basic, epidemiologic, and unclassified) and its various combinations.

RESULTS

The number of MCHC papers increased from 34,110 in 1966 to 65,028 in 1995, but the proportion of all Medline articles (18-21%) was relatively stable. There were remarkable long-term temporal stabilities in the proportions of MCHC papers of mothers and the four age groups of children. Most papers dealt with child (46%) and adolescents (45%), and only 11% studied mother and children together. Regression analysis indicated that a linear increase in number of MCHC papers in Medline (1053/year) was represented largely by single-age and combinations of age children, especially adolescence. However, the slope for mother-plus-children papers (113/year) was substantially higher than for mothers alone (64/year). Clinical papers (52%) were the dominant type of MCHC research, but the proportions of basic and epidemiologic papers and their combinations with clinical papers have increased substantially in the past decade.

CONCLUSIONS

There has been a dominance of clinical and child-related papers in MCHC research, which may be a reflection of restricted outlooks of specialists in the area. This may change soon if the tendency toward increasing numbers of basic and epidemiologic papers holds.

Prevalence of pre-obesity and obesity in urban adult Mexicans in comparison with other large surveys

OBJECTIVE

1. To estimate the prevalence of pre-obesity and obesity in a 1992 to 1993 national survey of the Mexican urban adult population. 2. To compare our findings with other national surveys and with data for Mexican Americans.

RESEARCH METHODS AND PROCEDURES

The national representative sample of the Mexican urban adult population included 8462 women and 5929 men aged 20 to 69 years from 417 towns of >2500 people. Body mass index (BMI), calculated from measured weight and height, was classified using the World Health Organization categories of underweight (BMI < 18.5 kg/m2), normal weight (BMI 18.5 to 24.9 kg/m2), pre-obesity (PreOB = BMI 25 to 29.9 kg/m2) and obesity (OB = BMI 30+ kg/m2). Estimates for Mexican Americans were calculated from U.S. survey data.

RESULTS

Overall, 38% of the Mexican urban adult population were classified as pre-obese and 21% as obese. Men had a higher prevalence of pre-obesity than women did at all ages, but women had higher values of obesity. Both pre-obesity and obesity increased with age up to the age range brackets of 40 to 49 or 50 to 59 years for both men and women. Both pre-obesity and obesity prevalence estimates were remarkably similar to data for Mexican Americans from 1982 through 1984. Comparison with other large surveys showed that countries differed more in the prevalence of obesity than of pre-obesity, leading to differences in the PreOB/OB ratio, and that countries also differed in the gender ratio (female/male) for both pre-obesity and obesity.

DISCUSSION

Pre-obesity and obesity were high in our population and increased with age. Our approach of characterizing large surveys by PreOB/OB and gender ratios appeared promising.

[Relationship between leptin and insulin blood levels in obese and lean Chilean women]

BACKGROUND

Leptin, a product of ob gene and insulin blood levels, are proportional to the amount of adipose tissue. Insulin could have an independent regulatory effect on leptin secretion.

AIM

To assess the relationship between serum leptin and plasma insulin levels in obese and lean Chilean women.

MATERIAL AND METHODS

One hundred forty five women, aged 20 to 60 years old, were studied. Weight, height, waist and hip circumference, fasting blood glucose, insulin and leptin levels were measured. Insulin resistance was assessed using the homeostasis model assessment. The relationship between different variables was determined using multiple linear regression, variance analysis and non parametric correlation.

RESULTS

Leptin serum concentrations were positively correlated with body mass index, insulin plasma levels and degree of insulin resistance. The association of leptin with insulin was independent of body mass index and persisted after adjustments by body fat distribution and age.

CONCLUSIONS

Insulin and insulin resistance are associated to high blood leptin levels and this association is independent of the degree of adiposity and body fat distribution.

Hypertension in urban Mexico: the 1992-93 national survey of chronic diseases

The purpose of this work is to estimate the prevalence of hypertension in the urban population of Mexico. We studied a multistage national sample representative of the urban population in 417 cities of over 2500 people. The blood pressure of 14 657 individuals (6053 men and 8604 women) aged 20-69 years was measured after a 5-min rest using a standard mercury sphygmomanometer. The survey personnel had been previously trained and standardised. The main results show a crude prevalence of hypertension, as defined by the JNC VI, of 28.1% in women and 37.5% in men (27.2% and 37.1% age-adjusted). Both genders exhibited a trend of increasing hypertension with age. In individuals under 50 years of age, women had lower rates than men, but the difference disappeared in the older groups. The awareness of hypertension (28%) as well as the success of treatment (22%) were low in our sample. Our results had more similarities than differences with respect to those observed in other national surveys. It is concluded that hypertension in Mexico is an important public health problem similar to that seen in developing and developed nations. Efforts should be aimed at strengthening measures to prevent and control hypertension in Mexico. More information is needed of the sort obtained from longitudinal studies.

[Clinical nutrition training in medical schools of Mexico]

OBJECTIVE

To describe the efforts carried out to strengthen nutrition education in Mexican medical schools. Emphasis was placed on the status previous to the program implementation, the design of a new basic curriculum, and the description of the main program strategies implemented.

METHODS

a) Analysis of available medical curricula; b) Application of a questionnaire to the school deans; c) Assessment of knowledge of nutrition of advanced medical students; d) Design of a basic curriculum of clinical nutrition; e) Edition of a textbook; f) Design and implementation of program strategies to strengthen nutrition education.

RESULTS

Clinical nutrition was not a topic included in most curricula analyzed and, when present, it was incorporated to related clinical subjects. Usually, emphasis was placed on basic topics of nutrition while clinical and applied subjects were considered less frequently. Lack of a specialized faculty and weakness of teaching infrastructure were some problems identified. A basic curriculum adaptable to different contexts was designed, and a textbook on clinical nutrition was edited and published. Training and formation of nutrition specialists were among the key programs implemented.

[What is known about micronutrients in Mexico]

OBJECTIVE

To update the information on micronutrients in Mexico regarding: 1. The research lines according to priority of the micronutrient, subjects affected, and its focus (basic, clinical, epidemiological, operational). 2. The laboratory capacity available for micronutrient assays.

MATERIAL AND METHODS

We analyzed review articles of what has been published on micronutrients in Mexico since 1950. We also gathered information by questionnaire from the 16 research groups working in Mexico in the area of micronutrients.

RESULTS

We generated tables summarizing the situation of the six micronutrients which we identified as the most problematic in Mexico (vitamins A and C, and iron, iodine, zinc and calcium).

CONCLUSIONS

We reached 10 conclusions related to populations of study, research line priorities, and desirable operational studies.

Distortionless interferogram recording by use of holographic field lenses for fluid velocimetry

Two optical systems based on holographic field lenses are presented. They have been specifically designed for the CCD camera acquisition of the interferograms obtained from a fluid plane, when one uses holographic interferometry to measure fluid velocities. The use of these systems allows for easy recording of interferograms, all having the same size and position on the CCD, independent of the fluid-plane observation direction. The holographic lenses act as directional field lenses; they change the divergent beam that reaches the lens into a convergent beam that focuses on the camera aperture. These distortionless interferogram recording systems have been demonstrated in a Rayleigh-Bénard convective flow.

Velocity measurements in a convective flow by holographic interferometry

A holographic interferometry technique has been developed that can be used to measure the three components of the velocity field in a whole plane of a fluid flow simultaneously. The light scattered from an illuminated fluid plane is recorded on a hologram. Several interferograms are obtained in the reconstruction of the hologram. Each interferogram is automatically analyzed and produces quantitative information about one velocity component. Parameters that affect the quality of the interferograms are analyzed. The technique is demonstrated in a Rayleigh-Bénard convective flow. Holographic interferometry and particle image velocimetry techniques are compared.

Overweight and hypertension: data from the 1992-1993 Mexican survey

Data of the 1992-1993 Mexican Survey of Chronic Diseases in the Urban Adult Population were analyzed to investigate the effects of age and sex on the association between overweight and hypertension. Blood pressure, body weight, and height were measured in a group of 13,945 Mexicans aged 20 to 69 years living in towns and cities larger than 15,000 people. Hypertension was defined following the recommendations of the Joint National Committee for Detection, Evaluation, and Treatment of High Blood Pressure-V. Overweight was defined following the recommendations of the National Institutes of Health Consensus on Health and Obesity. The prevalence of types of hypertension was higher in men than in women, particularly in the groups of 20 to 39 years of age. Cross-classification of subjects according to the presence of hypertension and overweight confirmed the association between both variables. The odds ratio and 95% confidence intervals indicated that overweight was associated with systolic and diastolic hypertension and with isolated diastolic hypertension in women and, to a lesser extent, in men. This association was not found in the 60- to 69-year group in both sexes. Overweight did not show significant association with isolated systolic hypertension in both sexes. Results of a multiple logistic regression analysis of overweight on hypertension, controlling for age and sex, were consistent with these findings. It is suggested that other factors, independent of overweight, explain the observed gender-specific differences in the prevalence of hypertension in younger age groups. The hormonal environment of young women is one of the mentioned factors modifying the prevalence of hypertension in this group of the Mexican urban adult population.

[Coverage of Mexican articles and journals in the database Bibliomex Salud]

OBJECTIVE

To evaluate the coverage of Mexican journals and manuscripts of biomedical research in a Mexican data base (Bibliomex Salud) during its 10 years of existence (1985-1994).

MATERIAL AND METHODS

All the manuscripts published by a single Mexican journal Revista de Investigación Clínica (RIC) were searched for in Bibliomex: the absence of a RIC manuscript in Bibliomex was considered a failure. Also, the number and identity of the Mexican journals included in Bibliomex was also noted. From a total of 744 manuscripts 99 were excluded (22 non-Mexican, 25 nonindexable, and 52 initially not indexed by Bibliomex). The remainder (645) were classified according to starting year of indexing: originals since the first year; letters to the editor since 1990; and editorials and authors' replies since 1993.

RESULTS

Bibliomex started out with 21 Mexican journals and now has more than 50 (12 indexed during the 10 years, 27 for the last 5-9 years, and 16 for the last 1-4 years). Regarding manuscripts, Bibliomex had an 8% failure rate in originals (46/597) and letters (3/36), and 25% in editorials and authors' replies (3/12).

CONCLUSIONS

a) The coverage of Bibliomex has improved in its second half of life in the number of both journals and manuscripts indexed; b) the retrieval of information could be improved by two changes in the procedures of Bibliomex; c) Bibliomex seems to be a database which could be used to analyze Mexican research production at several levels (institutional, regional, and national).

The therapeutic approach to the control of hypertension. Its impact on health policy

The pharmacologic approach to the control of hypertension must consider both the clinical perspective and the Public Health approach policy in which social costs have to be balanced against benefits to the entire population. Cost-effectiveness analysis are at the core of decisions taken within this frame of reference. The issue of cost-effectiveness of preventive and therapeutic measures are crucial in the case of less developed countries. An analysis of studies undertaken in Mexico leads to the conclusion that, from a Public Health perspective, a program for the control of hypertension with a strong emphasis on drug therapy is likely to require a significant proportion of the health budget. Therefore, more emphasis must be placed on primary prevention based on modifications of life style.

Parity and the prevalence of overweight

OBJECTIVE

To assess the association between previous term pregnancies and the prevalence of overweight in a group of urban women, controlling for the influence of age.

METHODS

One thousand twelve women, living in middle and low socioeconomic areas of Mexico City, were interviewed at home and their reproductive histories studied. Height and weight were measured in a clinical setting using controlled procedures. Overweight (BMI > 25) was the dependent variable used to calculate odds ratios and to perform a multiple logistic regression analysis.

RESULTS

Age and parity were significantly associated with the prevalence of overweight. Controlling for age, two or more previous pregnancies significantly increased the magnitude of the association.

CONCLUSION

During the reproductive years parity seems to increase the risk of overweight in low and middle socioeconomic level urban women.

[Erythrocyte transketolases and Alzheimer disease]

Abnormalities of thiamin metabolism have been reported in senile dementia of Alzheimer's type (SDAT). Transketolases (TK) were studied in 21 patients with SDAT, 24 age-matched controls and 12 chronic alcoholics. Erythrocytes were assessed for their TK activity coefficient (TK-AC, normal value 8.4 +/- 12.6%) and affinity for thaimin pyrophosphate (Km TPP, normal value 17.8 +/- 8.3 mumol). Comparison between study groups and controls demonstrated increased TK-AC in SDAT (16.6 +/- 15.7%, P < 0.05) and chronic alcoholism (43.4 +/- 40.6%, P < 0.05), and increased Km TPP (38.3 +/- 25.2 mumol, P < 0.01) in SDAT only. These findings suggest structural abnormalities of TK rather than vitamin B1 deficiency in SDAT.

Effects of magnesium, high energy phosphates, piracetam and thiamin on erythrocyte transketolase

Erythrocyte transketolase activity coefficient (ETK-AC) and affinity for coenzyme (Km TPP) were assessed in 50 patients with transketolase abnormalities such as fibromyalgia or senile dementia of Alzheimer's type, before and after magnesium (Mg), thiamin+pyridoxine (B1,B6), high energy phosphates (HEP) (phosphocreatinine of adenosine triphosphate), and piracetam. Compared to 12 untreated patients, ETK-AC was significantly decreased with B1,B6 (P < 0.05, n = 10); Km-TPP was significantly decreased with HEP (P < 0.05, n = 20) and piracetam (P < 0.01, n = 5). In nine other patients treated with HEP + B1,B6 + magnesium, ETK-AC and Km TPP were both significantly decreased.

Prospective study of infection, colonization and carriage of methicillin-resistant Staphylococcus aureus in an outbreak affecting 990 patients

In the three years between November 1989 and October 1992, an outbreak of methicillin-resistant Staphylococcus aureus (MRSA) affected 990 patients at a university hospital. The distribution of patients with carriage, colonization or infection was investigated prospectively. Nosocomial acquisition was confirmed in at least 928 patients, 525 of whom were identified from clinical specimens as being infected (n = 418) or colonized (n = 107) by MRSA. An additional 403 patients were identified from screening specimens, of whom 58 subsequently became infected and 18 colonized. Screening of the nose, throat and perineum detected 98% of all carriers. Of the 580 infections in 476 patients, surgical wound, urinary tract and skin infections accounted for 58% of the infections. Of the 476 infected patients, death was attributable to MRSA infection in 13%. Colonization with MRSA was found in 127 patients and 42% of 165 colonized sites were the skin. Auto-infection from nasal carriage or cross-infection, probably via staff hands, seemed to be the most common mode of acquisition of MRSA infections.

[Organ transplantation as a health priority in developing countries]

The epidemiology profile of developing countries is in transition. While the prevalence of infectious and preventable diseases, malnutrition, and in general the health problems traditionally associated to the poor, is still high, the characteristic health profile of industrialized countries (i.e. chronic and degenerative diseases, accidents, violence, social pathology) is beginning to surface. This paper focuses on the need to consider organ transplantation as a health priority in developing countries, as an important element in the global strategy to cover both aspects of the health care demand.

Nd-YAG laser applications in surgical endoscopy: a single center comprehensive experience

A retrospective review of endoscopic procedures using the Nd-YAG laser was carried out for patients treated between September 1984 and November 1986. Two hundred twenty two procedures were performed on 104 patients (58M:46W) during this 26 month period. The study encompasses a unique period of time in this center, as it includes the initial use of the endoscopic laser technique, the learning curves associated with its application, and finally, the time when its use became routine. Treatment of tumors was the indication in 47 per cent of the cases. Gastrointestinal bleeding of benign cause was the indication in nearly half of the patients; arteriovenous malformations were the most common causes of bleeding. Laser photocoagulation of hemorrhoids was performed in 11 cases. Upper endoscopy was the route in 33 per cent of procedures. Anoscopy, flexible sigmoidoscopy, and colonoscopy were the routes in the remainder. The time spent on the procedure and the energy delivered were found to be variables of the type of lesion and the endoscopic route. Nd-YAG laser endoscopy can be used safely and effectively for a variety of bleeding and obstructive gastrointestinal conditions. Appropriate certification for granting of privileges to laser endoscopists is of utmost importance.