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.