Wearable pulmonary monitoring system with integrated functional lung imaging and chest sound recording: a clinical investigation in healthy subjects.

Objective.Current wearable respiratory monitoring devices provide a basic assessment of the breathing pattern of the examined subjects. More complex monitoring is needed for healthcare applications in patients with lung diseases. A multi-sensor vest allowing continuous lung imaging by electrical impedance tomography (EIT) and auscultation at six chest locations was developed for such advanced application. The aims of our study were to determine the vest's capacity to record the intended bio-signals, its safety and the comfort of wearing in a first clinical investigation in healthy adult subjects.Approach.Twenty subjects (age range: 23-65 years) were studied while wearing the vests during a 14-step study protocol comprising phases of quiet and deep breathing, slow and forced full expiration manoeuvres, coughing, breath-holding in seated and three horizontal postures. EIT, chest sound and accelerometer signals were streamed to a tablet using a dedicated application and uploaded to a back-end server. The subjects filled in a questionnaire on the vest properties using a Likert scale.Main results.All subjects completed the full protocol. Good to excellent EIT waveforms and functional EIT images were obtained in 89% of the subjects. Breathing pattern and posture dependent changes in ventilation distribution were properly detected by EIT. Chest sounds were recorded in all subjects. Detection of audible heart sounds was feasible in 44%-67% of the subjects, depending on the sensor location. Accelerometry correctly identified the posture in all subjects. The vests were safe and their properties positively rated, thermal and tactile properties achieved the highest scores.Significance.The functionality and safety of the studied wearable multi-sensor vest and the high level of its acceptance by the study participants were confirmed. Availability of personalized vests might further advance its performance by improving the sensor-skin contact.

Identification and analysis of stable breathing periods in electrical impedance tomography recordings.

Objective. In this paper, an automated stable tidal breathing period (STBP) identification method based on processing electrical impedance tomography (EIT) waveforms is proposed and the possibility of detecting and identifying such periods using EIT waveforms is analyzed. In wearable chest EIT, patients breathe spontaneously, and therefore, their breathing pattern might not be stable. Since most of the EIT feature extraction methods are applied to STBPs, this renders their automatic identification of central importance.Approach. The EIT frame sequence is reconstructed from the raw EIT recordings and the raw global impedance waveform (GIW) is computed. Next, the respiratory component of the raw GIW is extracted and processed for the automatic respiratory cycle (breath) extraction and their subsequent grouping into STBPs.Main results. We suggest three criteria for the identification of STBPs, namely, the coefficient of variation of (i) breath tidal volume, (ii) breath duration and (iii) end-expiratory impedance. The total number of true STBPs identified by the proposed method was 294 out of 318 identified by the expert corresponding to accuracy over 90%. Specific activities such as speaking, eating and arm elevation are identified as sources of false positives and their discrimination is discussed.Significance. Simple and computationally efficient STBP detection and identification is a highly desirable component in the EIT processing pipeline. Our study implies that it is feasible, however, the determination of its limits is necessary in order to consider the implementation of more advanced and computationally demanding approaches such as deep learning and fusion with data from other wearable sensors such as accelerometers and microphones.

Efficacy and safety of endoscopic submucosal dissection for colorectal neoplasia: a systematic review.

BACKGROUND AND STUDY AIMS: Endoscopic submucosal dissection (ESD) has been proposed for large colorectal lesions, due to the high risk of recurrence following endoscopic mucosal resection. However, data on the efficacy and safety of colorectal ESD are still controversial. The aim of the current systematic review was to assess the efficacy and safety of colorectal ESD. METHODS: A detailed Medline search of papers published during the period 1999-2010 was performed, using the search terms "Endoscopic submucosal dissection," "Colorectal neoplasia," "Colon," or "Rectum." Published studies that evaluated ESD for colorectal lesions were assessed using well-defined inclusion/exclusion criteria, including histological confirmation and surgery for complications. The process was independently performed by two authors. Forest plots on primary (i.e. histologically verified R0 resection and surgery for ESD complications) and secondary end-points were produced based on random-effect models. Heterogeneity was assessed using the I2 statistic. Risk for within-study bias was also ascertained. RESULTS: A total of 22 studies (20 Asian, two European) provided data on 2841 ESD-treated lesions. The per-lesion summary estimate of R0 resection rate was 88% (95%CI 82%-92%; I2=91%). At meta-regression, carcinoid vs. non-carcinoid series (R0 93% vs. 87%; P=0.04) and Asian vs. European series (R0 88% vs. 65%; P=0.03) appeared to explain the detected heterogeneity. The per-lesion summary estimate of surgery for ESD complications was 1% (95%CI 0%-1%) with a moderate degree of heterogeneity (I2=49%). However, subgrouping of these results according to histological tumor types was not available in the reviewed studies. CONCLUSIONS: ESD appeared to be an extremely effective technique to achieve R0 resection of large colorectal lesions. The very low rate of surgery for complications also shows the potential safety of this approach.

Dietary proteins on reproductive performance in three consecutive generations of rats.

The cumulative effects of the long-term consumption of the Regional Basic Diet (RBD) of Northeast Brazil on gestational and lactational performances were assessed in three consecutive generations of Sprague Dawley rats (n = 1,334). The animals were distributed into three groups: RBD (8% predominantly vegetable-based proteins), Control (8% casein) and Standard (22% casein). Primiparous fertilized rats aged 120 days old and their offsprings made up generation 1. Consecutive generations were obtained by mating products from previous generations. Statistical differences between groups and generations were analysed by the method of Kruskal-Wallis. In comparison with their respective controls, data for RBD-fed groups were as follows: decreased conception rates, gradual declines in gestational body weight gains and reduction in the mean number of youngs per litter; the weight loss of lactating rats aggravated in consecutive generations; suckling rats had lower values for birthweight and weight gain, higher values for death rates (including soon after weaning) and severe immaturity at weaning (21 days). This dietary experimental model proved to be valid in terms of providing information for further studies about the relationship between quality and quantity of dietary proteins in order to allow decisions on supplementary feeding programmes for people now most in need.

[The use of a multimix as a dietary supplement: study in rats]. / Uso de uma multimistura como suplementação alimentar: Estudo em ratos.

A Multimistura (MM)--sweet cassava (Manihot esculenta Crantz) leaf flour, wheat bran (Tritium aestivum L.), egg shell powder, pumpkin (Cucurbita Spp) and sunflower (Heliantus annus) seed flours--was added to a mixture of Beans, 7% (Phaseolus vulgaris) and Rice, 3% (Oryza sativa) and its effects, were assessed in weanling, male albino (Wistar) rats (n = 60). Animals were divided into 6 groups: groups 1, 2 and 3 were fed beans + rice + multimixture (B + R + MM), beans + rice (B + R) and 10% Casein, respectively; the remaining groups were maintained on a protein-free diet (PFD) for 14 d and then submitted to the same feeding protocol. Microbiological assays were performed in all MM samples. The Coefficient of Digestablity (CD), the Food Efficiency Ratio (FER), Protein Efficiency Ratio (PER), Net Protein Utilization (NPR), serum hemoglobin (Hb) and hematocrit (Ht), carcass total lipids were determined. Rats had their liver, brain, gonads, testes, spleen and left kidney removed for wet dry weights. Liver samples were histologically examined. The Mann-Whitney test was used. The protein content of B + R diet increased slightly after MM addition (0.23 g/100 g). Three out of four MM samples had moulds and yeasts. CD values were 90% and 70% for casein and B + R + MM-fed rats, respectively. The highest values for FER, PER and NPR were seen in the casein-fed rats without protein depletion. The casein-fed group had heavier organs (wet and dry weights) and higher values for carcass fat and serum Hb and Ht. Steatosis was present in both groups, with or without protein depletion. Short or long-term MM consumption, at least under our experimental conditions, had no significant effects on investigated parameters.

[Longevity of malnourished rats fed with the regional basic diet (RBD) of the northeast of Brazil]. / Duración de la vida en ratas desnutridas, utilizando dieta básica del nordeste brasileño.

The effects of a Regional Basic Diet (RBD) on life expectancy and growth were studied in 23 Sprague-Dawley rats from mothers fed RBD since fecundation. These animals were compared with 20 rats from mothers fed the balanced control diet (22% protein). At weaning, the animals were fed their mothers diet and the weight was recorded every week until death. Sex related differences were not detected among RBD-fed animals; the growth curve was similar for both sexes. The critical points of acceleration and deceleration of the growth rate were not defined for these rats. Survival for RBD-groups decreased until 75 d of age and was unchanged between 75 and 450 d of life. From the 459 th d to the 589 th d of life deaths occurred successively. Controls survived until the 860 th d of life. Data point out the need for improving the basic food pattern of the region to prevent, among other things, a low life expectancy for the northeastern population.

Rat models of protein and protein-energy malnutrition.

Two animal models of infantile malnutrition were produced where some aspects of carbohydrate metabolism can be studied: protein-depleted (PD, "kwashiorkor") rats, fed a protein-free diet for 18 days, starting 3 days before weaning, and chronically malnourished animals during suckling (PED, "marasmus") where 20-22 pups were fed by the same dam. PED and PD rats were sacrificed at 21 and 36 days of age, respectively. Body weight was 35% in PD, and 50% in PED groups when compared to their age-matched controls. After an overnight fast, some of the PD animals presented with low blood glucose levels, and the levels of lactic and pyruvic acids were depressed in PED, while lactic acid was increased in PD animals. Blood glucose utilization was reduced in PED, and increased in PD rats, while the opposite was true for the kidney gluconeogenic capacity. When compared to the respective control values, muscle glycogen was high in both groups, while the level of liver glycogen was unchanged. The rate of muscle glycolysis was decreased in both groups. These results are in agreement with clinical observations, suggesting that these models may be used to study some of the metabolic changes brought about by infantile malnutrition.

[Nutritional and taste properties of canned cowpeas (Vigna unguiculata (L.) Walp). I. Effect of the canning process]. / Propriedades nutricionais e sensoriais do feijao macáçar verde (Vigna unguiculata (L) Walp) enlatado. I. Efeito do processo de enlatamento.

The effects of canning in brine on cowpea quality (Vigna unguiculata (L.) Walp) were determined. Beans were steamed-blanched at 100 degrees C for 2 minutes, and then canned and autoclaved at 121 degrees C for 10 minutes. These samples were compared to home-cooked cowpea samples through physicochemical, sensory and biological analyses. Significant reductions (p < or = 0.01) in canned bean composition as to values for protein, carbohydrate and fiber were determined when compared to cooked samples. The available methionine content was identical for both processes, but canned beans produced higher values of available lysine than cooked ones. Values for Net Protein Ratio (NPR)--3.19 showed that canning did not affect protein quality of canned beans. These results were similar to the ones found in home-cooked cowpeas (2.96). According to physicochemical analyses, quantitative losses did not seem to affect protein quality, and acceptance of product was found to be satisfactory to tasters.

[Nutritional and taste properties of canned cowpeas (Vigna unguiculata (L.) Walp. II. Effect of storage]. / Propriedades nutricionais e sensoriais do feijão macáçar verde (Vigna unguiculata (L.) Walp) enlatado. II. Efeito do armazenamento.

In order to evaluate the effects of storage on nutritional and sensory properties of canned cowpea (Vigna unguiculata (L.) Walp), a batch of 180 cans was stocked at room temperature (22 degrees C to 32 degrees C) for a period of six months. At intervals of 0, 30, 90 and 180 days, 26 samples collected randomly were submitted to physicochemical, sensory and biological analyses. Significant statistical reductions (p < or = 0.01 to p < or = 0.05) were observed due to storage time, having this significance increased for proteins after 90 days and for lipids after 30 days, as well as a decrease on the amino acid values, thus indicating the occurrence of chemical reactions, although acceptance of the product was found to be satisfactory throughout the whole experiment. No evidence was discovered of the presence of gas producer microorganisms. According to physicochemical analyses, quantitative losses in protein, lipids, available methionine and lysine did not seem to affect protein quality, in spite of a significant reduction (p < or = 0.01) in weight gain and Coefficient of Food Efficiency of samples stored for 180 days when compared to those freshly canned on day 0, though values for Net Protein Ratio (NPR) showed no discernible decrease; these data lead to the conclusion that canned cowpeas stored can be consumed without, restrictions, in spite of the slight decrease in biological value caused by the time of storage.

[Bean and rice mixtures of high protein value (author's transl)]. / Misturas de feijão e arroz de alto valor protéico.

The optimum content of different rice (Oryza sativa) and bean (Vigna unguiculata L.) combinations was studied in Albino rats. The mixture containing 3 g of rice proteins, corresponding to 41g of rice "in natura", and 7 g of bean protein, corresponding to 59 g of bean "in natura", presented the highest protein efficiency ratio and the feed efficiency ratio. Since the limiting amino acid of this mixture was methionine, new assays using varying levels of this amino acid as a supplement were carried out. The PER of normal rats as well as the "plateau" value of previously protein depleted rats were highest when 0.2% methionine was added to the mixture. The net protein utilization (NPU) confirmed these findings. The values attained after the addition of other amino acids were not higher than those attained by the mixture containing 7 g of bean protein and 3 g of rice protein supplemented with 0.2% methionine. The PER and the NPU values came close to those of milk.

[Nutritive value of sunflower seeds (Helianthus annus) (author's transl)]. / Valor nutritivo da torta da semente de girassol (Helianthus annus).

The nutritive value of sunflower seeds (Helianthus annus) was studied and compared to that of casein. Thirty-six male rats, Wistar strain, aged 23 days, were divided into two groups and fed (a) a sunflower cake meal diet, and (b) a casein diet. The results indicate that due to its high protein level (52.06%) and coefficient of digestibility (95 CD) sunflower can be used as a feeding formula although its PER does not recommend its use as a milk substitute.