Design of a Multisensory Device for Tomato Volatile Compound Detection Based on a Mixed Metal Oxide-Electrochemical Sensor Array and Optical Reader

Insufficient control of tomato ripening before harvesting and infection by fungal pests produce large economic losses in world tomato production. Aroma is an indicative parameter of the state of maturity and quality of the tomato. This study aimed to design an electronic system (TOMATO-NOSE) consisting of an array of 12 electrochemical sensors, commercial metal oxide semiconductor sensors, an optical camera for a lateral flow reader, and a smartphone application for device control and data storage. The system was used with tomatoes in different states of ripeness and health, as well as tomatoes infected with Botrytis cinerea. The results obtained through principal component analysis of the olfactory pattern of tomatoes and the reader images show that TOMATO-NOSE is a good tool for the farmer to control tomato ripeness before harvesting and for the early detection of Botrytis cinerea.

Wearable system for outdoor air quality monitoring in a WSN with cloud computing: Design, validation and deployment

Breathing poor-quality air is a global threat at the same level as unhealthy diets or tobacco smoking, so the availability of affordable instrument for the measurement of air pollutant levels is highly relevant for human and environmental protection. We developed an air quality monitoring platform that comprises a wearable device embedding low-cost metal oxide semiconductor (MOS) gas sensors, a PM sensor, and a smartphone for collecting the data using Bluetooth Low Energy (BLE) communication. Our own developed app displays information about the air surrounding the user and sends the gathered geolocalized data to a cloud, where the users can map the air quality levels measured in the network. The resulting device is small-sized, light-weighted, compact, and belt-worn, with a user-friendly interface and a low cost. The data collected by the sensor array are validated in two experimental setups, first in laboratory-controlled conditions and then against referential pollutant concentrations measured by standard instruments in an outdoor environment. The performance of our air quality platform was tested in a field testing campaign in Barcelona with six moving devices acting as wireless sensor nodes. Devices were trained by means of machine learning algorithms to differentiate between air quality index (AQI) referential concentration values (97% success in the laboratory, 82.3% success in the field). Humidity correction was applied to all data.

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.

Portable Electronic Nose Based on Digital and Analog Chemical Sensors for 2,4,6-Trichloroanisole Discrimination

2,4,6-trichloroanisole (TCA) is mainly responsible for cork taint in wine, which causes significant economic losses; therefore, the wine and cork industries demand an immediate, economic, noninvasive and on-the-spot solution. In this work, we present a novel prototype of an electronic nose (e-nose) using an array of digital and analog metal-oxide gas sensors with a total of 31 signals, capable of detecting TCA, and classifying cork samples with low TCA concentrations (≤15.1 ng/L). The results show that the device responds to low concentrations of TCA in laboratory conditions. It also differentiates among the inner and outer layers of cork bark (81.5% success) and distinguishes among six different samples of granulated cork (83.3% success). Finally, the device can predict the concentration of a new sample within a ±10% error margin.

Electronic nose application for the discrimination of sterilization treatments applied to Californian-style black olive varieties

BACKGROUND

Olive oil continues to be the main destination for olives. The production of table olives is increasing. 'Californian-style' processes are among the most frequently employed to produce oxidized olives. Sensory evaluation requires the development of an instrumental detection method that can be used as an adjunct to traditional tasting panels.

RESULTS

An electronic nose (E-nose) was used to classify two varieties of olives following exposure to different sterilization. Principal component analysis (PCA) revealed that both varieties had different volatile profiles. Sensory panel evaluations were similar for both. Partial least squares-discriminant analysis (PLS-DA) obtained from the E-nose was able to separate the two varieties and explained 82% of total variance. Moreover, volatile profiles correctly classified olives according to sterilization times recorded up to 121 °C . The only exception was at F₀  ≥ 22 min, at which a plot of PCA outcomes failed to differentiate scores. E-nose data showed similar results to those produced from the volatile analysis when grouping samples were sterilized to F₀  ≥ 18 min, at the same time distinguishing these samples from those subjected to less intense thermal treatments. A partial least squares (PLS) chemometric approach was evaluated for quantifying important olive quality parameters. With regards to validation parameters, R P 2 pertaining to perceived defect was 0.88, whilst R P 2 pertaining to overall assessment was 0.78.

CONCLUSIONS

E-nose offers a fast, inexpensive and non-destructive method for discriminating between varieties and thermal treatments up to a point at which cooking defects are highly similar (from F₀  = 18 onwards). © 2021 Society of Chemical Industry.

Characterization of Polyphenol and Volatile Fractions of Californian-Style Black Olives and Innovative Application of E-nose for Acrylamide Determination

Californian-style black olives require a sterilization treatment that produces a carcinogenic contaminant, acrylamide. Thus, this compound was evaluated in two different olive cultivars using an electronic nose (E-nose). The sterilization intensity had a significant influence on the final phenol concentrations, acrylamide content, and volatile compounds. Increasing the sterilization intensity from 10 to 26 min (F0) reduced the phenol content, but it promoted acrylamide synthesis, leading to a wide range of this toxic substance. The Ester and phenol groups of volatile compounds decreased their content when the sterilization treatment increased; however, aldehyde and other volatile compound groups significantly increased their contents according to the thermal treatments. The compounds 4-ethenyl-pyridine, benzaldehyde, and 2,4-dimethyl-hexane are volatile compounds with unpleasant odours and demonstrated a high amount of influence on the differences found after the application of the thermal treatments. The “Manzanilla Cacereña” variety presented the highest amount of phenolic compounds and the lowest acrylamide content. Finally, it was found that acrylamide content is correlated with volatile compounds, which was determined using multiple linear regression analysis (R² = 0.9994). Furthermore, the aroma of table olives was analysed using an E-nose, and these results combined with Partial Least Square (PLS) were shown to be an accurate method (range to error ratio (RER) >10 and ratio of performance to deviation (RPD) >2.5) for the indirect quantification of this toxic substance.

[An update on parathyroid carcinoma]

Parathyroid carcinoma is a rare malignant disease that presents as a sporadic or familial primary hyperparathyroidism (PHP). The latter is associated with some genetic syndromes. It occurs with equal frequency in both sexes, unlike PHP caused by parathyroid adenoma that is more common in women. It should be suspected in cases of severe hypercalcemia, with high parathyroid hormone levels and a palpable cervical mass. Given the difficulty in distinguishing between parathyroid carcinoma and adenoma prior to the surgery, the diagnosis is often made after parathyroidectomy. The only curative treatment is complete surgical resection with oncologic block resection of the primary tumor to ensure free margins. Adjuvant therapies with chemotherapy or radiation therapy do not modify overall or disease-free survival. Recurrences are common and re-operation of resectable recurrent disease is recommended. The palliative treatment of symptomatic hypercalcemia is crucial in persistent or recurrent disease after surgery since morbidity and mortality are more associated with hypercalcemia than with tumor burden.

A Thyroid Genetic Classifier Correctly Predicts Benign Nodules with Indeterminate Cytology: Two Independent, Multicenter, Prospective Validation Trials

Background: Although most thyroid nodules with indeterminate cytology are benign, in most of the world, surgery remains as the most frequent diagnostic approach. We have previously reported a 10-gene thyroid genetic classifier, which accurately predicts benign thyroid nodules. The assay is a prototype diagnostic kit suitable for reference laboratory testing and could potentially avoid unnecessary diagnostic surgery in patients with indeterminate thyroid cytology. Methods: Classifier performance was tested in two independent, ethnically diverse, prospective multicenter trials (TGCT-1/Chile and TGCT-2/USA). A total of 4061 fine-needle aspirations were collected from 15 institutions, of which 897 (22%) were called indeterminate. The clinical site was blind to the classifier score and the clinical laboratory blind to the pathology report. A matched surgical pathology and valid classifier score was available for 270 samples. Results: Cohorts showed significant differences, including (i) clinical site patient source (academic, 43% and 97% for TGCT-1 and -2, respectively); (ii) ethnic diversity, with a greater proportion of the Hispanic population (40% vs. 3%) for TGCT-1 and a greater proportion of African American (11% vs. 0%) and Asian (10% vs. 1%) populations for TGCT-2; and (iii) tumor size (mean of 1.7 and 2.5 cm for TGCT-1 and -2, respectively). Overall, there were no differences in the histopathological profile between cohorts. Forty-one of 155 and 45 of 115 nodules were malignant (cancer prevalence of 26% and 39% for TGCT-1 and -2, respectively). The classifier predicted 37 of 41 and 41 of 45 malignant nodules, yielding a sensitivity of 90% [95% confidence interval; CI 77-97] and 91% [95% CI 79-98] for TGCT-1 and -2, respectively. One hundred one of 114 and 61 of 70 nodules were correctly predicted as benign, yielding a specificity of 89% [95% CI 82-94] and 87% [95% CI 77-94], respectively. The negative predictive values for TGCT-1 and TGCT-2 were 96% and 94%, respectively, whereas the positive predictive values were 74% and 82%, respectively. The overall accuracy for both cohorts was 89%. Conclusions: Clinical validation of the classifier demonstrates equivalent performance in two independent and ethnically diverse cohorts, accurately predicting benign thyroid nodules that can undergo surveillance as an alternative to diagnostic surgery.

Triangular Test of Amanita Mushrooms by Using Electronic Nose and Sensory Panel

This work aims to advance understanding of the differentiation of mushroom species through electronic devices that use sensors of various technologies and techniques for pattern recognition, comparing mainly volatile substances that emanate from them. In this first phase, the capacity of human olfaction to differentiate between the smell released by different wild mushrooms of the genus Amanita was analyzed by means of a triangular sensory test, comparing later the data to those obtained for the same samples with an electronic nose in a similar test. The results, still very preliminary, encourage imagining the wide application that these techniques will have and the feedback that this application can suppose for the training of the sense of human olfaction.

Wireless Sensor Network Combined with Cloud Computing for Air Quality Monitoring

Low-cost air pollution wireless sensors are emerging in densely distributed networks that provide more spatial resolution than typical traditional systems for monitoring ambient air quality. This paper presents an air quality measurement system that is composed of a distributed sensor network connected to a cloud system forming a wireless sensor network (WSN). Sensor nodes are based on low-power ZigBee motes, and transmit field measurement data to the cloud through a gateway. An optimized cloud computing system has been implemented to store, monitor, process, and visualize the data received from the sensor network. Data processing and analysis is performed in the cloud by applying artificial intelligence techniques to optimize the detection of compounds and contaminants. This proposed system is a low-cost, low-size, and low-power consumption method that can greatly enhance the efficiency of air quality measurements, since a great number of nodes could be deployed and provide relevant information for air quality distribution in different areas. Finally, a laboratory case study demonstrates the applicability of the proposed system for the detection of some common volatile organic compounds, including: benzene, toluene, ethylbenzene, and xylene. Principal component analysis, a multilayer perceptron with backpropagation learning algorithm, and support vector machine have been applied for data processing. The results obtained suggest good performance in discriminating and quantifying the concentration of the volatile organic compounds.

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.

Bluetooth gas sensing module combined with smartphones for air quality monitoring

This study addresses the development of a miniaturized (60 × 60 mm) Wireless Sensing Module (WSM) for environmental application and air quality detection. The proposed prototype has six sensors: one for humidity, one for ambient temperature (SHT21 from Sensirion), and four for gas detection (MiCS-4514, MiCS-5526 and MiCS-5914 from SGX Sensortech). The core of the system is based on a high performance 8-bit microcontroller, model PIC18F46K80, from Microchip. The obtained data values were transmitted to the Smartphone through a Bluetooth communication module and a home-developed Android app. The discrimination capability of the module is tested with 10 volatile organic compounds (acetone, acetic acid, benzene, ethanol, ethyl acetate, ethylbenzene, formaldehyde, toluene, xylene, and dimethylacetamide) and the effect of humidity and drift of the sensors is also studied. Results show that 88.33% and 92.22% success rates in classification stage are obtained using Multilayer Perceptron with BackPropagation Learning algorithm and Radial-Basis based Neural Networks, respectively.

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.

A 10-Gene Classifier for Indeterminate Thyroid Nodules: Development and Multicenter Accuracy Study

BACKGROUND

In most of the world, diagnostic surgery remains the most frequent approach for indeterminate thyroid cytology. Although several molecular tests are available for testing in centralized commercial laboratories in the United States, there are no available kits for local laboratory testing. The aim of this study was to develop a prototype in vitro diagnostic (IVD) gene classifier for the further characterization of nodules with an indeterminate thyroid cytology.

METHODS

In a first stage, the expression of 18 genes was determined by quantitative polymerase chain reaction (qPCR) in a broad histopathological spectrum of 114 fresh-tissue biopsies. Expression data were used to train several classifiers by supervised machine learning approaches. Classifiers were tested in an independent set of 139 samples. In a second stage, the best classifier was chosen as a model to develop a multiplexed-qPCR IVD prototype assay, which was tested in a prospective multicenter cohort of fine-needle aspiration biopsies.

RESULTS

In tissue biopsies, the best classifier, using only 10 genes, reached an optimal and consistent performance in the ninefold cross-validated testing set (sensitivity 93% and specificity 81%). In the multicenter cohort of fine-needle aspiration biopsy samples, the 10-gene signature, built into a multiplexed-qPCR IVD prototype, showed an area under the curve of 0.97, a positive predictive value of 78%, and a negative predictive value of 98%. By Bayes' theorem, the IVD prototype is expected to achieve a positive predictive value of 64-82% and a negative predictive value of 97-99% in patients with a cancer prevalence range of 20-40%.

CONCLUSIONS

A new multiplexed-qPCR IVD prototype is reported that accurately classifies thyroid nodules and may provide a future solution suitable for local reference laboratory testing.

Frequency of frailty and its association with cognitive status and survival in older Chileans

Background

Age-associated brain physiologic decline and reduced mobility are key elements of increased age-associated vulnerability.

Objective

To study the frequency of frailty phenotype and its association with mental health and survival in older Chileans.

Methods

Follow-up of ALEXANDROS cohorts designed to study disability associated with obesity in community-dwelling people 60 years and older living in Santiago, Chile. At baseline, 2,098 (67% women) of 2,372 participants were identified as having the frailty phenotype: weak handgrip dynamometry, unintentional weight loss, fatigue/exhaustion, five chair-stands/slow walking speed and difficulty walking (low physical activity). After 10–15 years, 1,298 people were evaluated and 373 had died. Information regarding deaths was available for the whole sample.

Results

The prevalence of frailty at baseline (≥3 criteria) in the whole sample was 13.9% (women 16.4%; men 8.7%) and the pre-frailty prevalence (1–2 criteria) was 63.8% (65.0% vs 61.4%), respectively. Frailty was associated with cognitive impairment (frail 48.1%; pre-frail 21.7%; nonfrail 20.5%, P<0.001) and depression (frail 55.1%; pre-frail 27.3%; nonfrail 18.8%, P<0.001). Logistic regression models for frailty adjusted for sex and age showed a strong association between frailty and mild cognitive impairment (MCI) (odds ratio [OR] =3.93; 95% CI: 1.41–10.92). Furthermore, an important association was found for depression and frailty (OR =2.36; 95% CI 1.82–3.06). Age- and sex-adjusted hazard ratios (HRs) for death showed an increased risk with increasing frailty: pre-frail HR =1.56 (95% CI: 1.07–2.29), frail HR =1.91 (95% CI: 1.15–3.19); after adjustment by age and sex, a higher risk of death was observed for people identified as frail (HR =1.56, P=0.014) and pre-frail (HR =1.30, P=0.065). MCI and dementia were also risk factors for death (MCI: HR =1.69, P<0.027; dementia: HR =1.66, P=0.016).

Conclusion

Frailty is highly prevalent and strongly associated with cognitive impairment and depression in older Chileans. The risk for death was higher for frail people, but underlying cognitive impairment is a key component of the lower survival rate.

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.

Febrile neutropenia in the tropics: a description of clinical and microbiological findings and their impact on inappropriate therapy currently used at an oncological reference center in Colombia

INTRODUCTION

Febrile neutropenia is a common complication of chemotherapy treatment of malignant hematological diseases. However, there is insufficient information regarding the infectious complications of febrile neutropenia in our country. Objective. We will evaluate the microbial characteristics of bacterial and fungal isolates and the clinical outcome of patients with febrile neutropenia who received medical attention at an oncological reference center in Colombia.

MATERIALS AND METHODS

A prospective case series included patients with histologically confirmed oncological disease, who were admitted because of febrile neutropenia or presented with febrile neutropenia during hospitalization. Patients with benign hematological diseases were excluded. Demographic, microbiological, and clinical features as well as treatment and outcome information from patients with febrile neutropenia were obtained. We performed univariate and multivariate analyses, with mortality defined as the outcome.

RESULTS

One hundred and thirty episodes of febrile neutropenia were identified in 104 patients. The mean patient age was 19, and 53% of the patients were male. Approximately 86% of the episodes occurred in patients with hematological disorders. An infectious site was identified in 65% of patients; 41% and 24% of the febrile neutropenia pateints´ episodes exhibited a localized infectious focus and developed bloodstream infections, respectively. The majority of infections were found in blood, urine, gastrointestinal tract, and soft tissue. Distribution analysis of microbiological isolates revealed 46.4% Gram-negative bacilli, 38.4% Gram-positive cocci, 8% fungi, and 7.1% parasites; there was a 7.7% mortality rate. Appropriate empirical antimicrobial therapy was a protection-related factor in multivariate analyses (OR= 0.17; 0.034 - 0.9 95% CI; p= 0.037).

CONCLUSIONS

The mortality rate was relatively low and comparable to the rate reported by developed countries. Inappropriate empirical antimicrobial therapy was the main factor associated with mortality.

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).

Predictive equations for stature in the elderly: A study in three Latin American cities

AIM

The aim of this study was to develop predictive equations based on anthropometric data to estimate stature in people 60 years and older in Latin America.

DESIGN

Population-based cross-sectional study in three Latin American cities.

SUBJECTS

Sample sizes were n=1657 (Sao Paulo, Brazil), n=1004 (Santiago, Chile) and n=995 (Mexico City, Mexico).

METHOD

The prediction equations were fitted by stepwise linear regression analysis. For each country and sex, samples were randomly split into two sub-samples (training and validation sub-samples) using the cross-validation method.

RESULTS

Stepwise regression analysis in the training sample revealed that only knee-height and age had a significant effect on the prediction of height. The values of the shrinkage statistic were below 0.1 indicating the reliability of the prediction equations. The regression equations had standard errors of estimate ranging from 3.3 cm (Chile), 3.6 cm (Brazil) and 4.0 cm (Mexico) for women, and 3.7 cm (Mexico and Chile) and 3.8 cm (Brazil) for men.

CONCLUSIONS

Sex-specific stature prediction equations based on knee-height and age were obtained from large representative samples from selected cities of Latin America.

[Multivariate study of the evolution of body dimensions in elderly Chilean women]

Although in medical research the use of longitudinal data to analyze short time periods is frequently required, it does not permit the use of classic statistical methods for chronological series. The objective of this study is to present the possibility and plausibility of using the STATIS method (Structuration des Tableaux A Trois Indices de la Statistique), an explorative method for data analysis, in a study of the body composition of a sample of 57 women over 68 years of age in Santiago, Chile who were observed over a period of 30 months. The variables analyzed (measured every 6 months) were the following anthropometric measurements: weight, height, arm circumference, calf circumference, waist circumference, hip circumference and knee height. The results obtained suggested a regular chronological evolution during the first 24 months of observation with a change in structure after 30 months of the study, thereby classifying subjects according to body composition.

Impact of clinic interventions on the rate of influenza vaccination in pregnant women

OBJECTIVE

To assess the impact of interventions in a prenatal clinic on the influenza vaccination rate in pregnant women.

STUDY DESIGN

This retrospective study of women receiving care in a university prenatal clinic examined the impact of several interventions to increase immunization rates implemented over 2 years. Influenza vaccination rates were assessed before and after the interventions, which included provider and staff education, stocking of the vaccine in the clinic and implementation of standing orders.

RESULTS

Influenza vaccination rates in pregnant women increased from <1% to 37%. Standing orders were the most important intervention for increasing immunization rates. Patients who received care in the certified nurse midwife clinic were more likely to be vaccinated, while those who received care in a high-risk obstetric clinic were less likely.

CONCLUSION

Interventions to improve influenza vaccination rates among pregnant women, particularly standing orders, are effective. These interventions should be implemented nationally in all prenatal care clinics.

Indicadores antropométricos, composición corporal y limitaciones funcionales en ancianos

BACKGROUND

Functional limitations limit the independence and jeopardize the quality of life of elderly subjects.

AIM

To assess the association between anthropometric measures and body composition with functional limitations in community-living older people.

MATERIAL AND METHODS

Cross-sectional survey of 377 people > or = 6 5 years old (238 women), randomly selected from the SABE/Chile project. Complete anthropometric measurements were done. Handgrip muscle strength was measured using dynamometers. Body composition was determined using Dual-Energy X-Ray Absorptiometry. Functional limitations were assessed using self reported and observed activities.

RESULTS

Body mass index was strongly associated with fat mass (men r =0.87; women r =0.91) and with lean mass (men r =0.55; women r =0.62). Males had significantly greater lean mass (48.9 kg vs 34.9 kg), and bone mass than females (2.6 kg vs 1.8 kg) and women had higher fat mass than men (26.3 kg vs 22.9 kg). The prevalence of functional limitations was high, affecting more women than men (63.7% vs 37.5%, p <0.01). Functional limitations were associated with lower handgrip strength in both sexes. In the multiple regression models, with functional limitations as dependent variable and anthropometric measures as contributing variables, only hand grip strength had a significant association (negative) with functional limitations in both genders. Age was also a significant risk factor for functional limitations among women.

CONCLUSIONS

Hand grip strength was strongly and inversely associated with functional limitations. Handgrip dynamometry is an easy, cheap and low time-consuming indicator for the assessment of functional limitations and the evaluation of geriatric interventions aimed to improve functional ability.

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.