Have there been changes in the application of mechanical ventilation in relation to scientific evidence? A multicenter observational study in Mexico. / ¿Se han producido cambios en la aplicación de la ventilación mecánica en relación con la evidencia científica? Estudio multicéntrico en México.

OBJECTIVE: The main study objectives were to describe the practice of mechanical ventilation over an 18-year period in Mexico, and estimate changes in mortality among critical patients subjected to invasive mechanical ventilation (IMV). DESIGN: A retrospective subanalysis of a prospective observational study conducted in 1998, 2004, 2010 and 2016 was carried out. SETTING: Intensive Care Units (ICUs) in Mexico. PARTICIPANTS: Adult patients consecutively enrolled in the ICU during one month and who underwent IMV for more than 12hours or noninvasive mechanical ventilation for more than one hour. Follow-up was performed up to a maximum of 28 days after inclusion. INTERVENTIONS: None. PRINCIPAL VARIABLES OF INTEREST: Age, sex, severity upon admission as estimated by SAPS II, parameters of daily arterial blood gases, treatment and complication variables, date and status at discharge from the ICU and from hospital. RESULTS: A total of 959 patients were included in 81 ICUs. Tidal volume (vt) decreased significantly both in patients with acute respiratory distress syndrome (ARDS) criteria (estimated 8.5ml/kg b.w. in 1998 to 6ml/kg in 2016; P<0.001) and in patients without ARDS (estimated 9ml/kg b.w. in 1998 to 6ml/kg in 2016; P<0.001). The ventilatory protective strategy (defined as vt < 6ml/kg or < 8ml/kg and a plateau pressure < 30cmH2O) was: 19% in 1998, 44% in 2004, 58% in 2010 and 75% in 2016 (P<0.001). The adjusted mortality rate in ICU over the 4 periods was: in 2004, odds ratio (OR) 1.05 (95% confidence interval, 95%CI: 0.73-1.72; P=0.764); in 2010, OR 1.68 (95%CI: 1.13-2.48; P=0.009); in 2016, OR 0.85 (95%CI: 0.60-1.20; P=0.368). CONCLUSIONS: The clinical practice of IMV in Mexican ICUs has been modified over a period of 18 years. The most significant change is the ventilatory strategy based on low vt. These changes have not been associated with significant changes in mortality.

n-3 Fatty acid supplementation in burned paediatric patients.

AIM: To determine the effect of dietary supplementation with n-3 fatty acids (FA) in paediatric burned patients who had less than 20% of total body surface affected. METHODS: Burned patients were randomly assigned into two groups, one of them received a supplement of n-3 FA during 5 weeks; the other group was considered as not n-3 supplemented burned group. A third group of no burned patients was selected as control. Blood samples were collected at admission and in burned groups at the final of the study. Plasma and erythrocyte phospholipid FA composition and some biochemical parameters related to the clinical evolution: total plasma proteins and C3 and C4 complement proteins were determined. RESULTS: In the early post-burn patients, there is an increase in saturated and monounsaturated FAs in plasma phospholipids, and a decrease in polyunsaturated FAs compared with control. These alterations are in favour of proinflammatory response to burn injury. In n-3 FA supplemented group, these changes were further reverted, and a favourable response in the amount of total plasma proteins and in C3 and C4 proteins of the complement system was demonstrated. CONCLUSION: Dietary n-3 FA supplementation might be beneficial for patients suffering thermal injury.

Long-chain polyunsaturated fatty acids in breast milk in La Plata, Argentina: relationship with maternal nutritional status.

Milk fat is the major source of energy for breastfed infants; it also supplies polyunsaturated fatty acids (PUFAs) essential for the development of brain, retina, and other organs. Maternal nutritional status is critical for the newborn, and little information exists regarding the PUFA status of vulnerable populations living in Southern regions. We studied the relationship between maternal nourishment and milk fatty acid composition. Mother nutritional status (normal, overweight or obese) was estimated on the body mass index. Milk protein, total lipid, and fatty acid composition were determined. Milk protein was not affected by mother's nutritional status. In obese mothers an increase in lipid content, linoleic acid, total n-6 and total PUFAs was observed comparing to the other groups. Disregarding the nutritional status, the ratio n-6/n-3 fatty acids was very high and the 22:6n-3 content was very low, when compared with those of mothers from other countries. This finding led us to urge Public Health officers to promote changes in the dietary habits of nursing women.

[Fatty acids of plasma and erythrocyte phospholipids in malnourished infants well-fed by breast feeding or formula]. / Acidos grasos de fosfolípidos en plasma y eritrocitos de lactantes desnutridos alimentados con leche materna o fórmulas.

Polyunsaturated fatty acids (PUFA) derived from essential fatty acids (EFA) play an important role in prenatal visual and neural development. Protein-energy malnutrition affects PUFA supply, and hence the synthesis of structural lipids during growth. Recently, some physiological studies reported abnormalities in the neurological functions of formula-fed infants relative to breast-fed. The purpose of our study was to assess whether fatty acid composition of the malnourished infant diet modifies plasma and erythrocyte phospholipid fatty acid composition. Three groups of full-term malnourished infants were selected according to their prior feeding. Two groups had received commercial formulas, one of them supplied with linoleic and alpha-linolenic acid, and the other supplied in addition with long chain PUFA from n-3 and n-6 series. The reference group of breast-fed infants was also enrolled. Plasma and erythrocyte phospholipid fatty acid composition was determined by gas-liquid chromatography. Those infants receiving formulas showed in plasma and erythrocyte phospholipids increased values in total saturated and monoethylenic fatty acids, and decreased values in polyunsaturated fatty acids from both n-6 and n-3 series, relative to that of breast-fed infants. These differences were more remarkable in the case of infants who received formula without PUFA. We conclude that in malnourished infants, a nutrient formula enriched with long chain fatty acids of n-6 and n-3 series could be helpful to achieve an erythrocyte and plasma fatty acid pattern similar to that obtained in breast-fed infants.

Acidos grasos de fosfolípidos en plasma y eritrocitos de lactantes desnutridos alimentados con leche materna o fórmulas. / [Fatty acids of plasma and erythrocyte phospholipids in malnourished infants well-fed by breast feeding or formula]

Polyunsaturated fatty acids (PUFA) derived from essential fatty acids (EFA) play an important role in prenatal visual and neural development. Protein-energy malnutrition affects PUFA supply, and hence the synthesis of structural lipids during growth. Recently, some physiological studies reported abnormalities in the neurological functions of formula-fed infants relative to breast-fed. The purpose of our study was to assess whether fatty acid composition of the malnourished infant diet modifies plasma and erythrocyte phospholipid fatty acid composition. Three groups of full-term malnourished infants were selected according to their prior feeding. Two groups had received commercial formulas, one of them supplied with linoleic and alpha-linolenic acid, and the other supplied in addition with long chain PUFA from n-3 and n-6 series. The reference group of breast-fed infants was also enrolled. Plasma and erythrocyte phospholipid fatty acid composition was determined by gas-liquid chromatography. Those infants receiving formulas showed in plasma and erythrocyte phospholipids increased values in total saturated and monoethylenic fatty acids, and decreased values in polyunsaturated fatty acids from both n-6 and n-3 series, relative to that of breast-fed infants. These differences were more remarkable in the case of infants who received formula without PUFA. We conclude that in malnourished infants, a nutrient formula enriched with long chain fatty acids of n-6 and n-3 series could be helpful to achieve an erythrocyte and plasma fatty acid pattern similar to that obtained in breast-fed infants.

Dietary long-chain fatty acids and visual response in malnourished nursing infants.

Polyunsaturated fatty acids (PUFAs) derived from essential fatty acids (EFAs) play an important role in prenatal visual and neural development. Protein-energy malnutrition affects PUFA supply, and hence the synthesis of structural lipids during growth. Recently, some physiological studies reported abnormalities in the visual function of formula-fed infants relative to breast-fed infants. The purpose of our study was to assess whether fatty acid composition of the malnourished infant diet modifies the visual function and erythrocyte phospholipid fatty acid composition. Three groups of full-term malnourished infants were selected. Two groups received commercial formulas. One of them supplied linoleic and alpha -linolenic acid: Formula I (FI), and the other supplied, in addition, long-chain PUFAs from n-3 and n-6 series: Formula II (FII). A reference group of breast-fed infants was also enrolled. Visual function was assessed using full-field flash electroretinography, and the erythrocyte phospholipid fatty acid composition was determined by gas-liquid chromatography. Those infants receiving the supplemented formula (FII) exhibited a similar retinal function to that of breast-fed infants. However, normal results were not achieved when infants were fed on the FI formula. In all groups, the results were correlated with the proportion of docosahexaenoic acid in erythrocyte phospholipid fatty acid composition. We conclude that in malnourished infants a nutrient formula enriched with long-chain fatty acids of n-6 and n-3 series could be helpful to achieve an erythrocyte fatty acid pattern and a visual function similar to that obtained in breast-fed infants.

Virus characterization and sequence of the fusion protein gene cleavage site of recent Newcastle disease virus field isolates from the southeastern United States and Puerto Rico.

Nine Newcastle disease virus (NDV) isolates obtained from Puerto Rico, Georgia, Alabama, Mississippi, and Texas were analyzed for in vivo pathogenicity, biological properties (hemagglutination of mammalian erythrocytes), and for sequence variation at the amino acid and sense RNA level of the fusion protein cleavage site. Intracerebral pathogenicity index values ranged from 0 to 0.3 and the intravenous pathogenicity index obtained for all isolates was 0. Four isolates hemagglutinated bovine erythrocytes, whereas no hemagglutination was observed using equine erythrocytes. By direct sequencing of reverse transcription polymerase chain reaction products, all the isolates had a predicted fusion cleavage sequence comparable to lentogenic NDV strains. Based on nucleotide sequence, the viruses could be grouped phylogenetically with the B1 vaccine-type virus. However, nucleotide sequences were not 100% similar to the B1 or La Sota NDV strains, indicating that minor genetic heterogeneity occurs among lentogenic field isolates of NDV.

Leishmaniasis eco-epidemiology in the Alpujarra region (Granada Province, southern Spain).

An eco-epidemiological study was carried out in the region of the Alpujarras (southern Spain, Granada province). Nine villages were chosen at random in 5 bioclimatic zones. A study of leishmaniasis in the canine and human populations, was carried out concentrating especially upon schoolchildren. A total of 615 dogs were screened, which represents almost 100% of the canine census. Of the screened dogs, 33 showed an antibody titer > or = 1/160 when tested by IFA (seroprevalence of 5.3%). Age, sex, activity, and clinical symptoms of each dog were taken into account. Among the human population, infection from Leishmania was studied using the Leishmanin skin test (LST). Of 1286 people who were tested, 568 (44.16%) were positive. Most of the subjects were schoolchildren (878; practically 100% of the pupils), of whom 288 (32.8%) tested positive. A close relation was seen to exist between the percentage of positive LST's and age. Finally, a close relationship was also observed between canine seroprevalence and percentage of schoolchildren who tested positive in the LST, in the 5 bioclimatic zones under consideration.

Protein-energy malnutrition during gestation and lactation in rats affects growth rate, brain development and essential fatty acid metabolism.

The influence of feeding a low protein diet to rat dams during gestation and lactation on lipid metabolism in pups was studied. Wistar rats were fed 5, 10, 15 and 25% dietary protein during gestation and lactation. Pup growth was monitored until weaning, and brain weight, protein concentration, proteolipid concentration and total lipid phosphorus concentration of brain were analyzed. The levels of fatty acids in dam milk as well as in pup liver phospholipids and brain prosphatidylcholine and phosphatidylethanolamine were determined. The progressive deprivation of maternal dietary protein produced a reduction in the total saturated fatty acid concentration of dam milk and an increment in the concentration of nonmetabolized linoleic acid. Pup body and brain weights as well as proteolipid, protein and total lipid phosphorus concentrations in brain were reduced in proportion to the degree of dietary protein deficiency. The products:precursor ratio of (n-6) fatty acids in liver phospholipids revealed an impairment in the elongation-desaturation pathway due to maternal protein deficiency. Both (n-6) and (n-3) polyunsaturated fatty acids within brain phosphatidylethanolamine were decreased by reduced maternal dietary protein intake, whereas only the linoleic acid-derived products were similarly affected in the corresponding phosphatidylcholine fraction. These results demonstrate the widespread and profound deleterious effects of low protein levels of maternal diet on the growth rate, brain development and fatty acid metabolism in rat pups.

Isoenzymatic characterization of the etiologic agent of canine leishmaniasis in the Granada region of southern Spain.

Sixty-four strains of Leishmania of canine origin, 61 visceral and three cutaneous, were isoenzymatically examined. These were collected from 23 sites in the Granada region in southern Spain. Starch gel was used in electrophoresis and a total of 15 enzymes were studied. All of the visceral strains and two of the cutaneous ones were identified as L. infantum zymodeme GR-1 (= MON-1). The third cutaneous strain was of a different zymodeme, belonging to the same complex but differing in the glucose-6-phosphate dehydrogenase (= 105) enzyme. This zymodeme has been named GR-16 and is equivalent to L. infantum MON-105; it has not been previously reported in dogs or any other animal reservoir.

Phlebotomus perniciosus Newstead, 1911, infection by various zymodemes of the Leishmania infantum complex in the Granada province (southern Spain).

This study presents the results of the isoenzymatic characterization of 21 strains of Leishmania of sandfly (P. perniciosus) origin from the Torvizcón area. It forms an integral part of a larger eco-epidemiological study of the Alpujarras (Granada province, Southern Spain). The strains analysed were shown to belong to the L. infantum complex based on the results of 15 enzymes. The electrophoretic profiles for the enzymes MDH, G6PD and NP1 have permitted the identification of four zymodemes: GR-1 (5 strains), GR-2 (2 strains), GR-3 (13 strains) and GR-7 (1 strain); only one of these zymodemes, GR-1, was found in the Torvizcón area in the vertebrate host (man and dog). This is the first time zymodeme GR-7 has been described.

[Effect of the administration of corn oil on the composition of fatty acids of plasma phospholipids in normal and malnourished infants fed with cow's milk]. / Efecto de la administración de aceite de maíz sobre la composición en ácidos grasos de los fosfolípidos del plasma de lactantes normales y desnutridos alimentados con leche de vaca.

The effect of corn oil diet administration on the essential fatty acids (EFAs) profiles was evaluated in plasma phospholipids from normal and malnourished cow's milk fed infants nursing infants. A control group of only breast-fed was also selected for this study. The fatty acid composition was determined by gas-liquid chromatography and used as biochemical variable for evaluating EFA status. A fall in the proportion of fatty acids concomitant with an increase in the saturated fatty acids, consistent with a pattern of essential fatty acid deficiency (EFAD) was observed in the cow's milk fed infants, either normal or malnourished (Table 2). The corn oil administration was capable of restoring the fatty acid profile to normal values, similar to the values of the control group of breast-fed infants, even in malnourished infants, although during the 15 days test they did not correct their clinical syndrome of malnutrition (Table 3). Calculation of the product-precursor of the linoleic acid provided evidence for the positive effect of the corn oil administration.

Efecto de la administración de aceite de maíz sobre la composición en ácidos grasos de los fosfolípidos del plasma de lactantes normales y desnutridos alimentados con leche de vaca. / [Effect of the administration of corn oil on the composition of fatty acids of plasma phospholipids in normal and malnourished infants fed with cows milk]

The effect of corn oil diet administration on the essential fatty acids (EFAs) profiles was evaluated in plasma phospholipids from normal and malnourished cows milk fed infants nursing infants. A control group of only breast-fed was also selected for this study. The fatty acid composition was determined by gas-liquid chromatography and used as biochemical variable for evaluating EFA status. A fall in the proportion of fatty acids concomitant with an increase in the saturated fatty acids, consistent with a pattern of essential fatty acid deficiency (EFAD) was observed in the cows milk fed infants, either normal or malnourished (Table 2). The corn oil administration was capable of restoring the fatty acid profile to normal values, similar to the values of the control group of breast-fed infants, even in malnourished infants, although during the 15 days test they did not correct their clinical syndrome of malnutrition (Table 3). Calculation of the product-precursor of the linoleic acid provided evidence for the positive effect of the corn oil administration.

Interrelationship between protein-energy malnutrition and essential fatty acid deficiency in nursing infants.

The influence of severe protein-calorie malnutrition on essential fatty acid (EFA) status was evaluated in nursing infants aged 2-5 mo. A control group of the same age and with normal weight-for-height was also selected for this study. The fatty acid pattern of total phospholipids from plasma and red blood cells (RBCs) was determined and then used as a biochemical variable for evaluating EFA status. A sharp fall in the relative percentage of n-6 (omega-6) fatty acids concomitant with an increase in the n-9 fatty acids in plasma and RBC phospholipids was observed. These results are consistent with the picture of EFA deficiency and showed that the deficiency state is well correlated with the severity of malnutrition. Calculation of the product-precursor ratio of polyunsaturated fatty acids derived from linoleic acid (18:2n-6) in RBC phospholipids provides evidence for an impairment in the elongation-desaturation pathway promoted by the protein-calorie malnutrition.