Fatty acid and sn-2 fatty acid composition in human milk from Granada (Spain) and in infant formulas

OBJECTIVE

To investigate differences in fatty acid and sn-2 fatty acid composition in colostrum, transitional and mature human milk, and in term infant formulas.

SETTING

Departament de Nutrició i Bromatologia, University of Barcelona, Spain and University Hospital of Granada, Spain.

SUBJECTS

One-hundred and twenty mothers and 11 available types of infant formulas for term infants.

DESIGN

We analysed the fatty acid composition of colostrum (n=40), transitional milk (n=40), mature milk (n=40) and 11 infant formulas. We also analysed the fatty acid composition at sn-2 position in colostrum (n=12), transitional milk (n=12), mature milk (n=12), and the 11 infant formulas.

RESULTS

Human milk in Spain had low saturated fatty acids, high monounsaturated fatty acids and high linolenic acid. Infant formulas and mature human milk had similar fatty acid composition. In mature milk, palmitic acid was preferentially esterified at the sn-2 position (86.25%), and oleic and linoleic acids were predominantly esterified at the sn-1,3 positions (12.22 and 22.27%, respectively, in the sn-2 position). In infant formulas, palmitic acid was preferentially esterified at the sn-1,3 positions and oleic and linoleic acids had higher percentages at the sn-2 position than they do in human milk.

CONCLUSION

Fatty acid composition of human milk in Spain seems to reflect the Mediterranean dietary habits of mothers. Infant formulas resemble the fatty acid profile of human milk, but the distribution of fatty acids at the sn-2 position is markedly different.

The influence of dietary palmitic acid triacylglyceride position on the fatty acid, calcium and magnesium contents of at term newborn faeces

The distribution of long-chain saturated fatty acids in triglycerides is different in infant formulas to that in human milk. In human milk, palmitic acid is predominantly esterified in the sn-2 position (beta-position) of the triglycerides, whereas in infant formulas, it is esterified mainly in the sn-1,3 positions (alpha,alpha'-positions). The specific distribution of the fatty acids in the triglyceride plays a key role in lipid digestion and absorption. We studied fatty-acid, calcium and magnesium composition in the faeces of three groups of at term newborn infants fed different diets: Group A (n=12) was fed from birth to 2 months with human milk (66% palmitic acid in beta-position), Group B (n=12) was fed with formula alpha (19% palmitic acid esterified in beta-position) for 2 months, and Group C (n=12) was fed with formula alpha during the first month and with formula beta (44.5% palmitic acid in beta-position) during the second month. Samples were taken at the end of the first month (t0) and at the end of the second month (t1). Groups A and C presented significantly lower contents of palmitic acid in faeces at t1 than at t0, whereas in Group B, amounts remained similar. Faecal calcium in Groups A and C decreased in the second month (t1), although the fall was no statistically significant. In Group B, calcium amounts showed no change. We found that infant formula beta when compared with infant formula alpha reduced significantly the contents of total fatty acids and palmitic acid in faeces. We conclude that palmitic acid in beta-position is, therefore, beneficial for term infants.

Diversity of free-living prokaryotes from a deep-sea site at the Antarctic Polar Front

To contribute to the understanding of deep-sea planktonic communities, we explored the prokaryotic diversity of a 3000 m deep site at the Antarctic Polar Front using molecular methods. Bacterial 16S rDNA-amplified sequences corresponded to the as yet uncultivated groups SAR11, within the alpha-Proteobacteria, and SAR324, within the delta-Proteobacteria, as well as to the gamma-Proteobacteria, Cytophagales, Planctomyces, Gram-positives, and the group of environmental sequences SAR406. Among them, gamma-proteobacterial sequences were the most abundant and diverse. Within Archaea, and using six different primer sets for 16S rDNA amplification, only euryarchaeotal sequences were retrieved. Most of them clustered with the Thermoplasma-related marine groups II and III, but some corresponded to a recently described group of marine sequences emerging at the base of haloarchaea. Our data suggest that gamma-Proteobacteria and Euryarchaeota may be dominant elements in terms of genetic diversity of the two prokaryotic domains in this deep-sea pelagic area.

Archaeal Biodiversity in Crystallizer Ponds from a Solar Saltern: Culture versus PCR

The culturable haloarchaeal diversity in a crystallizer pond from a solar saltern has been analyzed and compared with the biodiversity directly retrieved by analysis of rRNA genes amplified from the environment. Two different sets of culture conditions have been assayed: solid medium with yeast extract as carbon source and liquid media with either yeast extract or a mixture of fishmeal, Spirulina sp., and Artemia salina. Seventeen colonies grown on plates with yeast extract incubated at 30 degrees C were analyzed by 16S rDNA partial sequencing. Sixteen were closely related to haloarchaea of the genus Halorubrum; 13 of them to Halorubrum coriense, a haloarchaeon isolated from a solar saltern pond in Australia, which had not been previously isolated from the pond analyzed in this study; and one to Haloarcula marismortui. Liquid cultures were analyzed by ribosomal internal spacer analysis (RISA) and partial sequencing of the 16SrRNA genes. A total of 18 sequences were analyzed, 15 corresponding to RISA bands obtained from cultures, and 3 from the environmental sample used as inoculum. Thirteen sequences obtained from cultures were related to several Halorubrum species, and 2 to Haloarcula. One of the clones obtained directly from the environmental sample was distantly related to a Natronobacterium, whereas two were related to SPhT, the phylotype most frequently retrieved from this environment by culture independent techniques. Our results show an extremely low diversity for the haloarchaea retrieved by cultivation even when modifications to the standard technique are introduced.

A novel haloarchaeal-related lineage is widely distributed in deep oceanic regions

During our study of the 16S rRNA gene sequence-based archaeal diversity of a deep-sea site located at a 3,000 m depth at the Antarctic Polar Front, we detected several phylotypes ascribed to already known Group II and III Euryarchaeota, and a cluster of distinct sequences that branched off at the base of haloarchaea. The position of this lineage (marine Group IV) was very robust using distance (neighbour-joining) and maximum-likelihood methods. Subsequently, we designed specific primers for the detection of this archaeal group in other marine environments using polymerase chain reaction amplification and sequence comparison. Group IV archaea were found in the Antarctic area (across a gradient from the Southern ocean to the South Atlantic), and also in North Atlantic and Mediterranean waters. In all oceanic locations, Group IV archaea were never detected in surface waters, but were vertically distributed in the deepest part of the water column.

A Multicentre and stratified study of the attitude of medical students towards organ donation in Spain

INTRODUCTION

Medical students represent a new generation of medical thought, and if they have a favourable attitude towards organ donation this will greatly encourage its promotion.

OBJECTIVE

To analyse the attitude of medical students in Spanish universities towards the donation of their own organs and to determine the factors affecting this attitude.

MATERIAL AND METHODS

Type of study: A sociological, interdisciplinary, multicentre, and observational study in Spain.

STUDY POPULATION

Students studying a degree in medicine enrolled in Spain (n = 34,000).

SAMPLE SIZE

A sample of 9598 students (confidence of 99% and precision of ±1%), stratified by geographical area and academic year. Instrument of measurement: A validated questionnaire of attitude towards organ donation and transplantation (PCID-DTO RIOS) was self-administered and completed anonymously.

RESULTS

The questionnaire completion rate was 95.7% (n = 9.275). 80% were in favour of donation, 2% against and 18% were undecided. The following main variables were related to a favourable attitude: being of the female sex (Odds Ratio = 1.739); being in the sixth year of the degree (OR = 2.506); knowing a donor (OR = 1.346); having spoken about the subject with one's family (OR = 2.132) and friends (OR = 1.333); having a family circle that is in favour, more specifically, having a father (OR = 1.841), mother (OR = 2.538) or partner in favour (OR = 2.192); being a blood donor (OR = 2.824); acceptance of the mutilation of the body if it were necessary (OR = 2.958); and being an atheist or an agnostic (OR = 1.766).

CONCLUSIONS

Spanish medical students generally have a favourable attitude towards organ donation, although 20% are not in favour.

Ozonation of azo dye in a semi-batch reactor: a determination of the molecular and radical contributions

Azo dye ozonation was carried in a semi-batch reactor to evaluate both the molecular and radical contributions of ozone on the dye decay. From two mass balance equations, the simultaneous determination of mass transfer, self-decomposition and solubility parameters of ozone were determined; thus establishing the steady state conditions in the experimental system. The results of kinetic studies showed that the decay of azo dye was a pseudo-first-order reaction with respect to dye concentration and the overall rate constant increased with an increase in the pH, however declined with an increase in the dye concentration. Furthermore, from the overall rate constants obtained at various pH values a mathematical analysis of dye decay was performed, which provides a practical new method to quantify the radical and molecular contributions in the ozonation of azo dyes.

Direct determination by high-performance liquid chromatography of sn-2 monopalmitin after enzymatic lipase hydrolysis

An alternative method to determine the sn-2 monopalmitin in infant formulas was developed and validated. This method offers many advantages over the traditional methods. It follows the official method in the first steps, purification of the fat or oil through an alumina column, and subsequently the triglycerides are incubated with pancreatic lipase in order to obtain the sn-2 monoglycerides. In traditional methods the sn-2 monoglycerides are separated by preparative thin-layer chromatography and then, the 2-monoglycerides are converted into the corresponding fatty acid methyl esters and analysed by gas chromatography. In our method, separation, quantification and identification of the sn-2 monoglycerides were achieved by high-performance liquid chromatography with evaporative light-scattering detection. The detection limit (0.19 microg), quantification limit (0.38 microg), linearity range (r=0.999, range 1-200 microg) and precision (SD=1.10) show the suitability of the proposed method. This method is faster, cheaper and simple and does not consume large quantities of reagents and materials.

Physicochemical and microbiological profile of packed table olives

The water activity of different commercial products of table olives as well as their physicochemical and microbiological profiles were studied. Average values of water activity were 0.976, 0.977, and 0.990 for green, directly brined, and ripe (by alkaline oxidation) olives, respectively. Mean values of pH were 3.69, 3.92, and 6.52 while salt levels were 5.53, 4.98, and 2.55 for the same commercial products. In some of the commercial products of green and directly brined olives that were examined, a certain level of microorganisms was observed. Most of them were lactic acid bacteria and yeasts, the lactic acid bacteria being more abundant than the yeasts. Traditionally, this flora has not been considered harmful due to its resemblance to that found in natural and spontaneous fermentation. Spore-forming mesophilic aerobes, which can be considered contaminants from ingredient or product handling, were present in only some samples and were always at low levels. However, their detection does not cause any concern regarding safety because there is no reference showing that they can grow in any of the products studied given the physicochemical characteristics found.

Do Spanish Medical Students Understand the Concept of Brain Death?

Objective:

To analyze the level of understanding of the brain death concept among medical students in universities in Spain.

Methods:

This cross-sectional sociological, interdisciplinary, and multicenter study was performed on 9598 medical students in Spain. The sample was stratified by geographical area and academic year. A previously validated self-reported measure of brain death knowledge (questionnaire Proyecto Colaborativo Internacional Donante sobre la Donación y Transplante de Organos) was completed anonymously by students.

Results:

Respondents completed 9275 surveys for a completion rate of 95.7%. Of those, 67% (n = 6190) of the respondents understood the brain death concept. Of the rest, 28% (n = 2652) did not know what it meant, and the remaining 5% (n = 433) believed that it did not mean that the patient was dead. The variables related to a correct understanding of the concept were: (1) being older ( P < .001), (2) studying at a public university ( P < .001), (3) year of medical school ( P < .001), (4) studying at one of the universities in the south of Spain ( P = .003), (5) having discussed donation and transplantation with the family ( P < .001), (6) having spoken to friends about the matter ( P < .001), (7) a partner’s favorable attitude toward donation and transplantation ( P < .001), and (8) religious beliefs ( P < .001).

Conclusions:

Sixty-seven percent of medical students know the concept of brain death, and knowledge improved as they advanced in their degree.

Mineral and sensory profile of seasoned cracked olives packed in diverse salt mixtures

This work studies the effect of packing cracked seasoned olives with NaCl, KCl, and CaCl(2) mixture brines on their mineral nutrients and sensory attributes, using RSM methodology. The Na, K, Ca, and residual natural Mn contents in flesh as well as saltiness, bitterness and fibrousness were significantly related to the initial concentrations of salts in the packing solution. This new process led to table olives with a significantly lower sodium content (about 31%) than the traditional product but fortified in K and Ca. High levels of Na and Ca in the flesh led to high scores of acidity and saltiness (the first descriptor) and bitterness (the second) while the K content was unrelated to any sensory descriptor. The new presentations using moderate proportions of alternative salts will therefore have improved nutritional value and healthier characteristics but only a slightly modified sensory profile.

Comparison of two direct methods for the determination of fatty acids in infant feces

We have validated and compared two direct methods for the determination of fatty acids in feces by capillary gas chromatography. Method I consisted of esterification of fatty acids using acetyl chloride. Method II used boron trifluoride-methanol as esterification reagent. The two methods were assayed with and without previous freeze-drying of the fecal sample. We found that the two methods could be carried out without sample freeze-drying. Precision and recovery rates were determined and the results were satisfactory. Both methods gave similar results, but Method II has certain advantages over Method I, such as speed, safety, and better recovery rates.

Shifts in Composition and Activity of Oral Biofilms After Fluoride Exposure

Oral diseases are biofilm-mediated diseases caused by imbalances in the ecology of resident microflora. Among them, dental caries (tooth decay) is considered the most common disease worldwide, and toothbrushing, which physically eliminates the oral biofilm, is the most widespread prevention strategy. Although it is well established that fluoride increases enamel resistance to acidic pH and promotes tooth remineralization, its effect on the biofilm bacterial communities' composition and metabolism is not fully understood. We have grown in vitro oral biofilms and used 16S rRNA Illumina sequencing to study the effect of fluoride on DNA- and RNA-based bacterial populations. In addition, a metatranscriptomic approach has also been performed, in which total RNA has been sequenced to study gene expression profiles in the presence/absence of 500 ppm sodium fluoride. Our data show a lower pH drop and a clear shift in total and metabolically active bacterial composition after fluoride exposure. Streptococcus oralis was the species most affected, with a 10-fold reduction in both DNA and RNA samples, whereas Rothia mucilaginosa underwent an 8-fold increase in the DNA and S. salivarius a 4- and 5-fold increase in the RNA and DNA samples, respectively. The metatranscriptomes indicated that fluoride exposure induced a dramatic shutdown of sugar metabolism, including significant under-expression of different sugar transporters, fucosidases, and a pyruvate oxidase, among others. The reduction in saccharolytic organisms and the inhibition of sugar fermentation pathways by fluoride may therefore be considered instrumental for the beneficial effect of fluoride-containing oral hygiene products.

Evaluation of a combined anaerobic and aerobic system for the treatment of slaughterhouse wastewater

A laboratory scale anaerobic/aerobic (An/Ar) system, comprising an anaerobic filter (AF) coupled to an aerobic sequential batch reactor (SBR), was developed to treat wastewater from a slaughterhouse. The AF operated with organic loadings (OL) from 3.7 to 16.5 kg m(-3) d(-1) and a hydraulic retention time (HRT) ranging from 16 to 72 h. The efficiency of chemical oxygen demand (COD) removal was between 50 and 81% and was shown to be related inversely to the value of the OL. The production rate of methane was in the region of 411 mL per g of COD removed. On the other hand, the degradation of organic matter (OM) by an aerobic pathway in the SBR followed first-order kinetics with regard to OM concentration; 85% of the remaining OM from the AF was eliminated within 6 h of aeration, and over 95% of total OM was eliminated as COD within 9 h. The optimal treatment conditions in this system were found at OL = 11.0 kg m-3 d(-1) and HRT = 24 h in the AF, whereas the SBR was most efficient at 9 h of aeration.