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Passive elastic behavior of tendon tissue from rats subjected to different dietary treatments was characterized. For that purpose, twenty-four weanling Wistar rats (41.02 ± 0.16 g) were randomly distributed into four groups. During 88 days each group was fed on different diets: control diet and diets containing advanced glycation end products (AGEs) from glucose-lysine model system, from bread crust and bread dough, respectively. After the trial animals were sacrificed and tendon samples were extracted and tested mechanically to fracture in a uniaxial tensile test machine. A transversely-hyperelastic model was formulated based on stress-strain relationships and its parameters were fit to the experimental data using the Levenberg-Marquardt optimization algorithm. Material parameters were incorporated in a finite element model to study different stress-strain distributions in a muscle-tendon unit. Results show higher strains and stresses in the muscle belly when properties of a stiffer tendon associated with a diet rich in AGEs are included in the model. A real increase in this mechanical response of the tissue could imply possible pain in joint mobility.

Adolescence is an important period of nutritional vulnerability due to increased dietary requirements for growth and development. Iron needs are elevated as a result of intensive growth and muscular development, which implies an increase in blood volume; thus, it is extremely important for the adolescent's iron requirements to be met. Diet, therefore, must provide enough iron and, moreover, nutrients producing adequate iron bioavailability to favor element utilization and thus be sufficient for needs at this stage of life. Currently, many adolescents consume monotonous and unbalanced diets which may limit mineral intake and/or bioavailability, leading to iron deficiency and, consequently, to ferropenic anemia, a nutritional deficit of worldwide prevalence. Iron deficiency, apart from provoking important physiological repercussions, can adversely affect adolescents' cognitive ability and behavior. Accordingly, promoting the consumption of a varied, adjusted, and balanced diet by adolescents will facilitate iron utilization, benefiting their health both at present and in adulthood. This review discusses how physiological changes during adolescence can cause iron requirements to increase. Consequently, it is important that diet should contribute an appropriate amount of this mineral and, moreover, with an adequate bioavailability to satisfy needs during this special period of life.

Background: Maillard reaction products (MRP) improve food palatability and are linked to some positive biological actions. However, diverse negative consequences, some related to protein damage and mineral availability, have been established., Aim of Study: We investigated the effects of MRP, from a bread crust diet, on phosphorus bioavailability and tissue distribution in rats to determine whether these effects are related to the molecular weight of browning products., Methods: During a study period of 88 days, rats were fed either a control diet or one of the following: with bread crust as a source of MRP, or one with its soluble high molecular weight, soluble low molecular weight or insoluble fraction (bread crust, HMW, LMW and insoluble diets, respectively). In the final week, a phosphorus balance was performed, after which the animals were sacrificed and some organs removed to analyse phosphorus content. A second balance was carried out throughout the experimental period to calculate phosphorus retention., Results: Phosphorus balance in the last week was unchanged. However, considering the whole experimental period, a trend towards improved bioavailability, significant in the HMW group, was observed. Higher phosphorus concentrations were measured in the small intestine and bone., Conclusions: The consumption of MRP derived from bread did not alter phosphorus retention, due to increased bioavailability, especially concerning HMW compounds. The overall phosphorus body content remained unchanged and there were no changes in the bone, its principal metabolic destination. However, MRP consumption markedly raised phosphorus levels at the digestive level, especially when consumed as isolate fractions. The slower rate of stomach emptying is assumed to be related to this effect.

Objective: To evaluate Zn utilization and status among a sample of Spanish boys consuming a diet based on Mediterranean patterns., Design: Dietary Zn balance was assessed by means of Zn intake in food and Zn output in faeces and urine as measured by flame atomic absorption spectrophotometry. In addition, biomarkers of Zn status were analysed., Setting: Province of Granada, Spain., Subjects: Twenty healthy male adolescents aged 11-14 years, selected based on medical questionnaire, physical examination and nutritional survey of food habits and lifestyle., Results: Mean Zn intake was 11·36 (se 0·31) mg/d, 76% of the recommended value for Spanish adolescents. Zn absorption (2·53 (se 0·55) mg/d) was close to the value of 3·0 mg/d required for the growth spurt. Zn status biomarkers and growth parameters were within the normal values for this age group., Conclusions: Although a diet based on Mediterranean patterns is associated with factors which can affect Zn absorption, such as high consumption of phytate, its consumption in adequate amounts allows Zn status to be maintained during adolescence. Due to the importance of Zn in preventing growth and behavioural disorders among adolescents, long-term intervention trials to investigate the suitability of the Mediterranean diet with respect to Zn requirements at this time of life are needed.

Adolescence is an important period of nutritional vulnerability due to increased dietary requirements for growth and development and special dietary habits. Calcium needs are elevated as a result of the intensive bone and muscular development and thus adequate calcium intake during growth is extremely important to reach the optimum peak bone mass and to protect against osteoporosis in the adult age, a major public health threat whose incidence is increasing in Western countries. However, most children and adolescents worldwide fail to achieve the recommended calcium intake. The hormonal changes associated with the pubertal period promote greater mineral utilization, which needs to be satisfied with suitable calcium consumption. Diet, therefore, must contribute nutrients in sufficient quality and quantity to allow maximum bone mass development. Consequently, adolescents should be educated and encouraged to consume adjusted and balanced diets that, together with healthy lifestyles, enable optimal calcium utilization.

Objective: To examine the effects of consuming diets rich in Maillard reaction products (MRPs) on phosphorus bioavailability in male adolescents., Methods: A 2-wk randomized two-period crossover trial was performed among healthy male adolescents aged 11-14 y (n = 20), with a 40-d washout period. The diets consumed were rich (brown diet) or poor (white diet) in MRPs. Three-day balances were performed on the last of each dietary period, and fasting blood samples were obtained. Dietary phosphorus utilization was examined by phosphorus intake in diet and phosphorus output in feces and urine, as measured colorimetrically by the vanadomolibdate procedure. Serum phosphorus, parathyroid hormone, and total alkaline phosphatase were determined., Results: A tendency to increase daily phosphorus fecal excretion was observed subsequent to the brown diet consumption compared with the white diet (P = 0.10), which led to significant reductions in phosphorus apparent absorption (P = 0.03) and fractional absorption (P = 0.04). Values of apparent phosphorus retention and bioavailability tended to decrease after the high-MRP diet. Serum parameters analyzed remained unchanged between diets and were within normal values., Conclusion: The consumption of a rich-MRP diet in male adolescents had a negative influence on dietary phosphorus absorption, tending to decrease the phosphorus balance. Given the actual dietary habits of adolescents, possible long-term repercussions of this kind of diet should be studied., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Thermal processing of milk is a common practice. As milk is the main source of dietary calcium, this study aimed to assess the effects of overheating milk on calcium availability. Thus, thermally damaged milk (overheated, OH, milk; 3 cycles of sterilization at 116 °C, 16 min) was compared with UHT milk (150 °C, 6s) in 2 types of assays: in vitro and in vivo (rats). In addition, the greater Maillard reaction rate associated with thermal treatment in OH milk was confirmed by determining specific (furosine) and unspecific markers (CieLab color). A negative effect on calcium solubility was observed after in vitro digestion of OH milk compared with UHT milk. Feeding rats the diet containing OH milk as the protein source led to significantly lower values of apparent calcium absorption and retention than those found among animals fed the UHT milk diet. Whereas reducing the absorption appears to result mainly from the decreased food intake, the negative effect on retention seems to be due to factors derived from milk thermal damage, such as the formation of Maillard reaction products. It was concluded that milk-processing conditions warrant special attention to prevent impaired dietary calcium utilization. This may be especially important in situations where milk and dairy products are the main dietary components, such as in early infancy., (Copyright © 2010 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)

Background: The effects of pelleting on the extent of the Maillard reaction (MR) and on calcium, magnesium and zinc solubility and absorption were analysed in a conventional pre-starter diet for suckling piglets. Development was tested measuring colour, absorbance (280/420 nm), fluorescence, residual free lysine, furosine, hydroxymethylfurfural (HMF) and furfural contents before and after pelleting. Fluorescence, absorbance and mineral solubility were also measured after in vitro digestion of diets. The effects on mineral absorption were tested using Caco-2 cells., Results: MR indexes confirmed the development of the reaction during the pelleting of this particular diet compared with the meal diet. The CIE-Lab colour parameters showed a decrease in luminosity (L*) and progress of the colour to the red zone (a*) in the pelleted diet. A 36% decrease in free lysine content was observed. Significant correlations were observed between fluorescence intensity and furosine levels, HMF and furfural. The pelleting process did not modify calcium and magnesium solubility after in vitro digestion, but soluble zinc increased. The efficiency of calcium and zinc transport across Caco-2 cell monolayers was greater in the pelleted diet., Conclusions: Evidence of MR development is shown, resulting in various nutritional consequences. Optimisation of pelleting could result in a better formulation of diets for feedstuffs., ((c) 2010 Society of Chemical Industry.)

The effects of diets with different Maillard reaction products (MRPs) content on biological iron utilization were compared using in vitro/in vivo assays. Diets were rich (brown diet, BD) or poor (white diet) in MRP. In vitro studies included iron solubility after in vitro digestion of diets and iron transport across Caco-2 cells. In the human assay 18 healthy adolescent males (11-14 years) participated in a 2-wk randomized two-period crossover trial. Subjects collected urine and faeces on the last 3 days of each dietary period, and fasting blood samples were obtained after periods. In vitro dietary iron availability was significantly lower with the BD than the white diet (9.52 and 12.92%, respectively), as a consequence of the lower iron solubility after the in vitro digestion, but not as a result of decreased transport of the remaining soluble iron. The BD consumption increased iron fecal excretion ( approximately 1.4-fold) and significantly decreased its bioavailability ( approximately 2.7-fold), mainly due to the effects found at digestive level. Serum biochemical parameters related to iron metabolism remained unaltered. It is concluded the presence of MRP in the diet negatively affects iron bioavailability. As iron deficiency may be related to learning impairment and to reductions of cognitive and physical functions, possible long-term effects of excessive MRP intake during adolescence warrant attention.

The effects of the high intake of Maillard reaction products (MRP) on calcium availability in adolescents and across Caco-2 cell monolayers were examined. In a 2 week randomized two-period crossover trial, 18 male adolescents consumed two diets, named white diet (WD) and brown diet (BD), which were poor and rich in MRP, respectively. A 3 day balance was performed at the end of each period, and fasting blood samples were collected. Calcium solubility and absorption across Caco-2 cells were studied after the in vitro digestion of the diets. The in vitro assay showed similar solubility after the in vitro digestion and similar transport across Caco-2 cells. In accordance, calcium bioavailability in adolescents did not vary between the diets (%WD = 40.4 +/- 5.1, %BD = 38.2 +/- 3.6). Serum and urine biochemical parameters related to calcium status and bone metabolism remained unaltered. Only deoxypyridinoline values were significantly lower after consumption of the BD (13.0 +/- 1.1 compared to 18.3 +/- 2.1 nM/Mm Cr in the WD), possibly indicative of less efficient bone turnover during this period. As calcium acquired during adolescence is essential to maximize peak bone mass and to prevent osteoporosis, possible long-term effects of excessive MRP intake during this period warrant attention.

The effects of a diet based on Mediterranean patterns on iron bioavailability and iron status in adolescents were studied. The study was divided into two periods: basal period, in which 21 male adolescents consumed their habitual diet (basal diet); and nutritional intervention period, during which an experimental diet based on the Mediterranean model was consumed. Dietary iron utilization was studied by means of iron intake and iron output in faeces and urine, and iron status was analysed in fasting blood samples collected at the end of each period. No differences in total iron intake were found between diets, but consumption of the experimental diet increased iron absorption and retention compared with the basal diet. Biochemical parameters related to iron metabolism did not vary after the intervention period, although serum ferritin tended to increase. Therefore, a diet based on Mediterranean dietary patterns may improve dietary iron utilization during adolescence and may prevent iron deficiency.

Model Maillard reaction products were generated by heating glucose-lysine mixtures (GL) at 150 degrees C for different times (15, 30, 60, and 90 min). Samples were characterized by free lysine, browning, and UV-visible spectra and assessed for antioxidant properties, metal chelating ability, and effects on mineral absorption across Caco-2 monolayers. It was found that the capacity to retard lipid peroxidation in a model linoleic acid emulsion system increased with heating time up to 60 min and then leveled off, whereas the scavenging activity toward 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radicals increased in early periods of the reaction (15 and 30 min of heating) and decreased thereafter. The iron binding affinity of the different samples was not correlated with antioxidant properties, and iron transport in Caco-2 cells was unchanged between samples. On the contrary, copper chelating activity showed significant correlation with free radical scavenging activity and with copper absorption across intestinal cells. It can be concluded that severe heat treatment of GL mixtures maintained the ability to reduce lipid peroxidation but decreased the free radical scavenging activity. Moreover, antiradical activity, copper chelation ability, and positive effects on copper absorption were correlated and associated to compounds formed at early stages of the Maillard reaction.

Objective: To examine the effects of consuming a diet based on the Mediterranean patterns on calcium availability and metabolism in male adolescents., Design: A longitudinal study divided into two periods: a 3-day basal period, during which the subjects (n = 20; 12.9 +/- 1.14 years) consumed their usual diet (basal diet, BD), and a 28-day nutritional intervention period, in which an intervention Mediterranean-type diet - was consumed (ID)., Methods: Dietary calcium utilization was assessed by means of calcium intake in food and calcium output in feces and urine as measured by flame absorption spectrophotometry. In addition, markers of calcium metabolism (serum Ca, parathyroid hormone and total alkaline phosphatase) and bone resorption (urine deoxypiridinoline) were measured., Results: No differences in total calcium intake were found between the two diets, but food sources of dietary calcium varied significantly. Compared with the BD, the consumption of the ID resulted in significant increases in calcium absorption (approximately 40%, p = 0.04) and retention (approximately 80%, p = 0.008), and a considerable decrease in urinary calcium excretion (approximately 40%, p = 0.01).The variations observed in bone markers reflected a higher bone turnover rate after the ID consumption., Conclusions: A varied diet based on Mediterranean diet patterns during adolescence greatly improves dietary calcium utilization, which may help to maximize the peak bone mass and prevent related diseases, such as osteoporosis.

The transport and availability of hydroxymethylfurfural (HMF), an intermediary product of the Maillard reaction, was investigated in the Caco-2 cell line after in vitro gastrointestinal digestion. The study was carried out at two levels; (a) an HMF-spiked culture medium, and (b) digested commercial breakfast cereals (BC). In both assays, the higher the amount of HMF offered to the cells, the higher the absolute value of transported HMF. However, HMF availability and transport are not directly proportional to the initial HMF content since HMF is partly retained in the non-soluble fraction after digestion. In addition, HMF is degraded to some extent during the gastrointestinal digestion of both HMF-spiked cell medium and BC. Average HMF availability from three commercial breakfast cereals was 9.1% (4.98-12.99%). Variations in HMF availability may be related to the particular composition of each BC, where fibre could play an important role. On the other hand, possible metabolization into the cell should also be considered.

Contents of some indicators of the Maillard reaction (MR) in two diets adjusted to the adolescent requirements are compared: the A-diet, usually consumed by the adolescent population containing their preferred foods cooked by the culinary techniques more frequently chosen; and the B-diet, with the same foods, except those industrially processed and with high content of Maillard reaction products (MRP), cooked in softer processes to minimise the MR. Aliquots of a lunch-dinner (LD) and breakfast-afternoon (BA) snack pools separately from both diets were ground and lyophilised. Fluorescence associated to MRP, CIELAB colour parameters, furosine, hydroxymethylfurfural (HMF), carboxymethyllysine (CML) and sugar contents were investigated in the samples. Significant losses of lightness were manifested in A samples compared to the B ones. Fluorescence intensity was significantly higher in the LD and BA samples from the A-diet. Furosine measured in the A-diet was similar to that found in the B-diet. However, HMF content was significantly higher in the A-diet, as well as CML. Data showed significant higher levels of advanced MRP in the usual diet. Thus, MRP intake associated to alimentary pattern in the adolescence population might be studied in order to assess the health implications of the MRP consumption and its possible synergic effect with endogenous advanced glycation endproducts.

Background: Adolescents are nutritionally at risk because of their physiologic needs and dietary habits. Maillard reaction products (MRPs) are widely consumed by this population, mainly as a result of their high intake of fast food and snacks., Objective: We compared the effects of diets with different MRP contents on dietary protein utilization in adolescent males aged 11-14 y. The brown diet (BD) was rich and the white diet (WD) was poor in MRP content (hydroxymethylfurfural: 3.87 and 0.94 mg/kg; fluorescence intensity: 21.04% and 7.31%, respectively)., Design: In a 2-period crossover trial, 18 healthy adolescent males were randomly assigned to 2 groups. The first group consumed the WD for 2 wk, observed a 40-d washout period, and then consumed the BD for 2 wk. The second group received the diets in the opposite order. Subjects collected urine and feces on the last 3 d of each dietary period. Fasting blood samples were collected after both periods., Results: Compared with consumption of the WD, consumption of the BD resulted in 47% higher fecal nitrogen fecal excretion (P = 0.002), 12% lower apparent nitrogen absorption (P = 0.000), and a 6% lower nitrogen digestibility (P = 0.000). The apparent nitrogen retention and the utilization of ingested nitrogen did not differ significantly between the diets, although values after the BD tended to decrease. Serum biochemical variables related to nitrogen metabolism did not differ significantly., Conclusions: The consumption of a diet rich in MRPs negatively affects protein digestibility. The possible effects of an excessive intake of MRPs during adolescence warrant attention, and long-term effects should be considered.

Adolescence constitutes a period of nutritional vulnerability due to increased dietary requirements for growth and development and special dietary habits. A pilot trial was performed to evaluate the dietary calcium utilization among a sample of Spanish boys on their usual diets, in which the calcium intake and consumption of dairy products were as well examined. Nutrient and food intake was recorded using a 24-h dietary recall and a 2-d food consumption record for 21 subjects aged 11-14 years. Dietary calcium utilization was assessed by means of calcium intake in food and calcium output in faeces and urine as measured by flame atomic absorption spectrophotometry. Overall intake of dairy products was 399.3 +/- 22.1 g/d, and the single most consumed item was milk (72% of the total). An inverse relationship was found between dairy product consumption at breakfast (55% of the total) and BMI (p = 0.016, r = -0.5168). Dairy products contributed the majority of dietary calcium (66.9%). Mean calcium intake was 881.7 +/- 39.9 mg/d, 88% of the recommended value for Spanish adolescents. Net calcium absorption (271.7 +/- 51.7 mg/d) and retention (170.6 +/- 50.9 mg/d) seemed not to be sufficient to meet growth demands during puberty. The results shown that adolescents of the study absorbed 31% of dietary calcium and retained nearly 20% of the total intake, but dietary calcium intake and consumption of dairy products failed to meet recommended values. Optimizing calcium intake is of crucial importance among adolescents, to maximize calcium retention and to help prevent osteoporosis in later life.

The influence of glucose-lysine and glucose-methionine Maillard reaction products (MRPs) on calcium availability was studied in rats and in Caco-2 cells. Equimolar glucose/lysine and glucose/methionine mixtures (40% moisture) were heated (150 degrees C, 30 or 90 min) to prepare samples (GL30, GL90, GM30, and GM90, respectively). For 21 days, the rats were fed the AIN-93G diet (control group) or diets containing separately 3% of the heated mixtures (GL30, GL90, GM30, and GM90 groups, respectively). In the last week of the trial, a calcium balance was performed. On day 21, the animals were sacrificed and their livers and femurs removed for analysis of calcium levels. The GL30 and GM30 samples and the corresponding raw mixtures were used for Caco-2 cells experiments. Fecal excretion of calcium decreased and urinary elimination increased in the GM30 and GM90 groups. In accordance, increased calcium transport in Caco-2 cells was found in the presence of the GM30 sample, compared with the raw sample. Bone calcium concentration was lower among the animals consuming MRP diets, compared with the control group. The possible long-term effects of MRP intake on calcium deposition in the bone should be further studied to ascertain the implications on related diseases.

During food thermal treatment Maillard's reaction may occur, which implicates mainly the carbonyl groups of reductory sugars and amino protein groups. Maillard's reaction products (MRP) may interfere with mineral bioavailability because of modifications of their physical-chemical moiety in the food or the lumen, disrupting the absorption process or its normal metabolism. In this study, we sought to investigate MRP influence on issues related to Ca bioavailability in vitro and in vivo. Equimolar mixtures of glucose-lysine (GL) and glucose-methionine (GM) (40% moisture) were heated at 150 degrees C for 90 minutes (samples GL90 and GM90, respectively). In vitro solubility was measured by additioning each samples to a 3.75 mM Ca solution at intestinal pH and ionic strength; after shaking and centrifugation, soluble and insoluble calcium was determined. Three percent of GL90 and GM90 were individually added to the AIN93-G diet to obtain D-GL90 and D-GM90 diets. Three Wistar rats groups were fed for 21 days with both diets and with AIN93-G as control, carrying out calcium balance during last week and extirpating various organs after sacrifice. GM90 did not affect calcium solubility; GL90 reduced it slightly, remaining in both cases more than 94% soluble. D-GL90 and D-GM90 did not modify calcium bioavailability, with as effective usage as with the control diet (57.6 +/- 1.3%, 57.8 +/- 2.3% and 63.9 +/- 2.6% in control diet, D-GL90 and D-GM90, respectively). MRP intake produced, however, metabolic changes that decreased bone calcium, accumulating compensatorily in other organs.

Two series of derivatives were synthesised. In one series (R)-4-hydroxy-2-pyrrolidinone was used as a mimic of cyclic L-carnitine analogue and in the second series 3-amino-2-piperidinone was used as a cyclic ornithine analogue. N-Benzyloxycarbonyl derivatives of some amino acids were also prepared. The newly synthesised compounds were tested for their ability to inhibit Fas-activated apoptosis of human Jurkatt T-cell line. The results confirm the previously described anti-apoptotic activity of carnitine and indicate new carnitine and amino acid analogues (1, 3, 6, 7, 20) that inhibit Fas-induced apoptosis.

The purpose of this project was to study the modifications in nutrient composition, amino acid content, and protein quality of white tuna preserves after each of the thermal treatments involved in the canning process. Also the influence that a three years storage period at room temperature has on the nutritional quality of canned tuna was studied. The biological assays used for the study of the protein utilization were carried out on Wistar rats, fed on semi-synthetic diets for 12 days varying only the protein source, casein or tuna provided as follows: raw, cooked in brine, steamed, sterilized tuna, and canned tuna stored for three years. The sterilization process and storage time led to a great increase in the lipid content of the canned tuna and to a porcentual decrease in protein, and moisture content. Amino acid composition of canned and cooked tuna did not show great modifications compared to raw tuna. Neither protein digestibility nor biological value of the cooked, canned, and stored tuna showed any deterioration. The protein quality of white tuna meat preserves has been compared with preserves made up of red and white tuna meat.

We have previously shown 1,4-benzothiazine (1,4-B) derivatives induce thymocyte apoptosis in vitro and thymus cell loss in vivo. Apoptosis is mediated through a complex of biochemical events including phosphatidylcholine specific-phospholipase C (PC-PLC) activation, acidic sphingomyelinase (aSMase) activation and ceramide generation, caspase-8 and caspase-3 activation. As preliminary analysis of the structure-activity relationship (SAR) suggested some structural features were responsible for apoptosis, we synthesised several derivatives and tested for apoptosis activity at equimolar concentrations. In particular, we synthesised analogues that differed in the nature of skeleton (1,4-benzothiazine, 1,4-benzoxazine and 1,2,3,4-tetrahydroquinoline) and in the nature of side chain (imidazole, benzimidazole or piperazine as azole substituent; presence, absence or transformation of alcoholic group). Results of apoptosis induction indicate that transforming the 1,4-benzothiazine skeleton into 1,2,3,4-tetrahydroquinoline does not result in significant change. Transformation into 1,4-benzoxazine decreased activity. Replacing imidazole at the side chain with different piperazines also decreased activity while replacing it with benzimidazole does not change apoptotic activity. Finally, removal of the alcoholic group by dehydration to olefin, or by transforming it into ether, increased activity. Moreover, in an attempt to analyse further the SAR characteristics that are responsible for 1,4-B-activated apoptosis we tested the effect on caspase-8,-9 and-3 activation. 1,4-B analogues activate caspases and the structural requirements correlate with those responsible for apoptosis induction.

Sediment borne pesticides are one of the major routes of transport of pesticides into the aquatic environment and could affect biota living closely in contact with it. Sediment residues of DDT were found to be easily adsorbed (95.0%) and were released in hard water (8.4%) and seawater (0.1%). DDT and DDE sediment residues were released into sterile and nonsterile brackish water indicating minimal role of micro-organisms. DDT was detected in oyster and in mussel with an average of 46-62% in the shell, 19-31% in the tissues and 19-23% in the fluids. Most of the sediment residues were extractable and released residues in water were in the form of DDT. In the presence oysters, bound was transformed into extractable DDT in sediment after 30 days equivalent to 26% of the total concentration. Most biota residues were extractable and an average of 46% was transformed to DDE. Uptake of residues depend on whether the source of contamination was by direct addition to the water or through sediment residues, if food was given or not, if the source of sediment residues were either aged or freshly treated and if residues were extractable or non-extractable.

The effect of the heat treatment of casein in presence of reducing sugars on some aspects of Zn availability was investigated. Samples were prepared by mixing casein with glucose-fructose, and were used unprocessed (C) or heated (HC). Changes in Zn speciation after the in vitro digestion of the samples, both as part of a diet and in isolation, were studied. The uptake of soluble Zn from the digested samples was investigated in Caco-2 cells. After in vitro digestion, the percentage of precipitated Zn was significantly higher with the HC sample, both when digested alone and as a part of the diet. In assays with Caco-2 cells, a significant decrease in Zn uptake was observed when the uptake buffer contained the sample C digest, by comparison with the control buffer, without casein digest. When the digested heated mixture was added, Zn uptake by the cells was significantly lower than in either of the two other cases. It may be concluded that the heat treatment of casein in the presence of glucose-fructose has a negative effect on Zn availability because, after in vitro digestion, Zn insolubilization was enhanced and Zn uptake by the enterocyte was impaired, compared with the unheated mixture. In addition, the usefulness of Caco-2 cells in this kind of research has been shown.

The influence of the consumption of diets containing oil from either fresh sardines or fried sardines, under domestic conditions, on the dietary iron metabolism of rats has been investigated. Three groups of rats were fed, over 28 d, semipurified diets containing 8% of: olive oil (OO), fresh sardine (Clupea pilchardus) oil (SO) and oil from sardines previously fried in olive oil (FSO). Body mass and food intake were monitored and, during the periods 5-12 d and 21-28 d, faeces and urine were collected. At the end of the experiment, the animals were killed and blood, liver, spleen and a segment of skin were stored. Food intake and body mass decreased markedly in the SO rats. These parameters were slightly increased in the FSO group compared with OO. Iron absorption and retention were lower in SO than in OO or FSO. This was primarily caused by the poor food intake but also by the lower efficiency of absorption and high urinary Fe losses. Liver and spleen iron contents were reduced by half in SO compared with the other groups, partly owing to the smaller size of the organs, and liver Fe concentration also decreased. These results, together with the high total iron binding capacity, the decreased level of hemoglobin and total erythrocytic iron found in the SO animals, indicate that the consumption of fresh sardine oil as the only dietary fat resulted in iron depletion. The SO animals showed a higher Fe accumulation in skin than OO or FSO. It was concluded that a diet high in sardine fatty acid administered as a unique source of fat, can cause metabolic alterations including iron depletion, but these negative effects of sardine oil disappear with frying, probably owing to the exchange that takes place between fatty acids in the olive oil used in frying and those in the sardine oil.

A study was made of the influence of the consumption of white tuna (subjected to various thermal treatments) on the bioavailability of dietary iron. Biological assays were carried out on Wistar rats fed semi-synthetic diets varying only in the protein source, casein-methionine, or tuna provided in the following forms: raw, cooked in brine, sterilized with or without soybean oil, and canned and stored for a period of 1 or 3 years. Feed intake, the fecal and urinary excretion of iron, and the iron content of the liver were monitored. Absorption of iron was enhanced by consuming the diet containing raw white tuna. However, the beneficial effect of raw tuna was greatly reduced by cooking it in brine, and even more so by sterilization, especially in the presence of oil. The benefit was partly restored by storing the conserves for a period of 1 or 3 years. It is hypothesized that structural alterations to the protein caused by thermal processes can affect the solubility and bioavailability of iron.

The isolated ACTH deficiency is a scarcely diagnosed disease of heterogeneous nature. Two patients with isolated deficiency of ACTH in whom the initial diagnosis was of primary suprarrenal failure are reported. In the first case this diagnosis was performed after hospital admission for deterioration of the level of consciousness and the development of an acute suprarrenal crisis in the course of nosocomial pneumonia. In the second case the clinical manifestations began as weakness, anorexia, weight loss and lymphocytosis with eosinophilia. In both patients an increase in the thyrotropic hormone was detected leading to suspicion of the existence of associated primary hypothyroidism. Finally, several studies were carried out (basal measurements of cortisol and ACTH, stimulation with continual perfusion of ACTH, insulinic hypoglycemia, global study of adenohypophysary function, ACTH CRF release factor test, computerized tomography of the pituitary region) in both patients leading to the definitive diagnosis of isolated ACTH deficiency of idiopathic cause of possible pituitary origin without the existence of other associated hormonal deficiencies.

The objective of this study was to investigate the dietary zinc bioavailability in diets containing raw, cooked, steamed, and canned tuna as a protein source in the diet, and to evaluate different means of preparation, as well as various storage periods of the canned tuna, which was prepared according to industrial standards. Sterilized oil-free canned tuna was also made. The biological assays used for the study of the zinc utilization were carried out on Wistar rats fed with semi-synthetic diets for 12 days varying only in the protein source, which was casein-methionine or tuna provided as follows: raw, cooked in brine, steamed, sterilized with or without soybean oil, canned and stored for one or three years. Body weight, food intake, faecal and urinary zinc excretion, and zinc content in rat liver were monitored. No modifications were shown in food efficiency when diets including tuna were used, compared with those values from the casein-methionine diet. Thus, final body weight results were similar in all groups tested. Dietary zinc absorption was enhanced by consuming a raw white tuna diet. This beneficial effect disappeared after steaming or cooking in brine, but it was slightly recovered after sterilization with oil and storage of the canned tuna. Animals fed on the diets including the oil-free canned tuna, showed two or three times higher faecal and urinary zinc excretion than those fed on casein and canned tuna stored for 0, 1 or 3 years, reaching a negative balance. A negative effect was therefore found in both dietary and endogenous zinc utilization due to the consumption of oil-free canned tuna.

The relationship between physical exercise and diet in order to optimize performance is getting growing interest. This review examines protein needs and protein intakes as well as the role of protein in the body and the metabolic changes occurring at the synthesis and catabolic levels during exercise. Protein synthesis in muscle or liver, amino acids oxidation, glucose production via gluconeogenesis from amino acids, etc., are modified, and consequently plasma and urinary nitrogen metabolites are affected. A brief comment on the advantages, disadvantages and forms of different protein supplements for sportsmen is given.

Some aspects of zinc nutritive status in patients suffering from anorexia nervosa were evaluated. Basic anthropometric measurements, Zn levels in serum, urine and hair as well as serum alkaline phosphatase (ALP) and lactate dehydrogenase (LDH; Zn-dependent enzymes) and delayed dermal hypersensitivity were tested both in patients and in control subjects. The patients showed higher Zn levels in serum (123%), hair (85%) and urine (215%) than controls, whereas ALP and LDH values were 38 and 21%, respectively, lower than those from the control group. Half of the patients showed hypoergy, and less than 50% of them were able to show a normal immune response. These results suggest that Zn-dependent functions may be impaired in anorexia nervosa as a consequence of Zn unavailability.

Background: The diagnostic capacity of computed tomography (CT) of the pituitary gland in the diagnosis of prolactinomas is difficult to define in terms of specificity and sensitivity since, up to the present, there is no definite diagnostic test for prolactin producing tumors. The aim of this study is to establish the consistency of CT of the hypophysis in the diagnosis of the prolactinomas based on a concordance design., Methods: In the follow-up study of 48 patients diagnosed as affected of prolactinoma a concordance study was carried out on the blind lecture of 35 pituitary gland CT by two radiologists., Results: The degree of concordance for all the diagnosis (kappa = 0.58) was greater than what might be expected by chance. The degree of concordance was also different for the different diagnosis given by the two radiologists: empty sella turcica, kappa = 0.84 (p less than 0.01); macroprolactinoma, kappa = 0.68 (p less than 0.01); microprolactinoma, kappa = 0.45 (p less than 0.01) and normal sella turcica, kappa = 0.28 (NS)., Conclusions: CT of the hypophysis must be less sensitive (more false negatives) in cases of high prolactin due to microprolactinomas and less specific (more false positives) in cases of high prolactin due to a cause other than pituitary tumor, thereby making it a complementary diagnostic test to clinical evaluation and to prolactin determinations.

Some parameters relating nutritional utilization of Ca, Mg, Fe and Zn were studied in rats fed with diets including raw and fried fats in order to study more in depth the diet fat/mineral utilization interaction. Wistar rats having initial weights of 176 g were divided into two groups and fed isocaloric diets having 15% fat content as raw olive oil and fried olive oil (from 15 potato fryings), during pregnancy. Weight and dietary intake were controlled and mineral content changes in plasma, liver, spleen and carcass were assessed, as well as litter mineral uptake. Throughout the study, dietary intake of pregnant rats fed raw (R) and fried oil (F), body weight gain and final weight gain were similar. Serum Fe, Zn and Ca levels decreased at a similar rate in both groups. Liver Fe levels decreased more in the F group while spleen Fe decreased more in the R group, these changes started on day 18. Liver Zn levels did not show clear changes but spleen Zn decreased during the last three days of pregnancy. Carcass Ca levels of pregnant rats from the R and F groups did not show any differences at the end of pregnancy. Body weight gain, Ca, Mg, Fe and Zn uptake of the litter were similar in both groups throughout the study. The placentas and the offspring of treated rats showed similar absolute and relative mineralization values. These findings lead us to conclude that fried olive oil retained the same characteristics as raw olive oil regarding mineral utilization.

It was studied the levels of phosphorus in serum and urine in two groups of pregnant women. One group was advised to follow their usual intake and the other to supplement the diet with 750 ml of milk. A control group of healthy non pregnant women were conformed to the same protocol. Pregnant women that followed their usual intake had the same levels of serum phosphorus and maximum phosphate transport as controls. Pregnant women who had taken milk supplement showed in the second and third trimester of pregnancy significantly lower serum phosphorus and maximum phosphate transport levels than controls and also with respect to pregnant women in the first trimester. It suggests a possible influence of diet on these parameters. Both groups of pregnant women showed hyperphosphaturia through the three trimesters.

The influence of consumption of increasing ethanol solutions of 5, 7.5 and 10%/99.5% (v/v), on total body mineral composition, but particularly the ethanol effect on the contents of Ca, P, Mg, Zn, Na and K, for eight weeks was studied in the adult rat. Both females and males voluntarily lower their liquid intake when daily ethanol ingestion is about 1.4 and 1.7 g, respectively. These ethyl ingestions introduce some modifications in male body composition, but not in females, with an increase in the relative water content and a decrease of the carcass dry substance. The latter would be the main reason for the decrease in male body content of Ca, P, Zn, Mg and K, at least from the 7.5% v/v solution. Ca, P and Zn seem to be the most modified elements. Likewise, there are negative influences regarding Na, but they are not clearly evidenced until ethanol consumption reaches 1.9 g per day. Female body weight did not undergo any change, under any tested experimental conditions or their body ashes suffer any deterioration.

The effect of two Ca/P relations (2.1 y 4.5) in the diet on nutritive utilization of both minerals, egg production and egg characteristics (weight, size, resistence and shell Ca content) was studied. Nutritive utilization and absolute body retention of Ca were higher with a Ca/P relation of 4.5, while the lower Ca/P relation (2.1) produced a greater utilization of P, without differences as high as in the case of Ca. As a whole, the diet with a Ca/p relation = 2.1 was more efficiently utilized but egg production did not rise optimal levels got on the diet with a Ca/P relation = 4.5 Egg characteristics were similar with both treatments.

The influence of seasonal variations and gestation on 25(OH)D3 levels was studied in a group of women from Madrid, Spain, at different stages of pregnancy, during March and September. The objective was to observe the incidence of this climate and dietary factors. No variations were found in serum concentration of the metabolite throughout pregnancy in comparison with the controls, in either March or September. 25(OH)D3 values decreased after winter in both groups of women, although mean values were consistently higher than 16 ng/ml.

An oil involved in the 'toxic syndrome' and two similar mixtures of oils, one with and the other without added oleoanilides, were studied for their effects on the utilization of protein, calcium, magnesium, phosphorus, sodium, potassium and zinc. Forty-eight female Wistar rats initially weighing about 75 g were fed for 28 days on the same semi-synthetic diet containing: virgin olive oil, or a mixture of canbra oil (50%), refined olive-pomace oil (20%), grapeseed oil (20%) and animal fat (10%), or the same dietary mixture supplemented with either 700 ppm oleoanilides or the alleged toxic oil. Weight, food intake and nutritional balances were monitored. The food intake of the animals fed the toxic oil began to decrease at the end of the trial, producing a reduction in the amount of nutrients ingested, but no weight loss. This oil also negatively affected the digestion of protein, potassium, sodium and zinc, the mechanism of which, in the case of the first two, appears to be related to the source of the fat. It also decreased metabolic utilization while favouring protein catabolism and the elimination of phosphorus, magnesium and potassium. No substantial modifications were noted in the animals' bones.

An oil implicated in the Spanish "toxic syndrome" was studied for its effect on fat digestibility and adipose-tissue composition in rats. The effects produced by the mixture of oils and those induced by the presence of oleoanilides were assessed separately. For 4 wk, Wistar rats were fed diets containing either a mixture of oils similar to that constituting the toxic oil, the same mixture of oils supplemented with oleoanilides, or the toxic oil (which also contained oleoanilides) and were then compared with a group fed olive oil. Food consumption fluctuated sharply in the group fed the toxic oil, falling significantly in the last week of the study. The digestibility coefficient of the various fats was similar, although the rats fed the toxic oil did absorb less fat because of the lower intake. The nitrogen content of the periovarian adipose tissue was highest in the rats fed the toxic oil, and the adipose-tissue fatty acids most affected by this treatment were linoleic and linolenic acid. The delta-9 desaturase activity, measured in terms of the C16:1/C16:0 and C18:1/C18:0 ratios, was significantly less in the group fed the toxic oil, which suggests functional modifications of the adipocyte related to lipogenesis.

Five experiments were conducted in which various levels of calcium (Ca) and phosphorus (P) were fed to adult male quail (diets D-1: Ca = 1.54%, p = 0.80%; D-2: Ca = 3.20%, P = 0.81%; D-3: Ca = 1.57%, P = 1.66%; D-4: Ca = 3.40%, P = 1.71%; D-5: Ca - 2.20%, P = 0.81%). The interaction between Ca and P, and the effect on some nutritive hematic and osseous parameters were investigated for each diet. Feeding high P caused a body weight decrease in D-4 adult quail (P less than 0.05) and diminished food intake in the birds of trial D-3 (P less than 0.05). The results indicated that the excretion of Ca or P is a lineal function of its own intake. Neither the pattern of relationship between the intake and excretion of Ca was altered by the levels of phosphorus in the diets, nor the levels of calcium altered the pattern of P. With these levels of Ca and P interaction between both nutrients were not demonstrated. Plasma Ca levels and dry weight of femur as well as the ash content in them, were not significantly decreased, although the levels of the latter components were inferior in the groups fed non-adjusted diets in the Ca:P ratio (diets D-1, D-2, D-3 and D-4).

The influence of alimentary calcium deprivation on the nutritional utilization of phosphorus and its corporal retention, after ingestion of diethylstilbesterol has been studied in quail. When female quail are given a highly calcium-deficient diet, egg-laying stops and there follows a substantial decrease in phosphorus utilization and retention, as well as a clear drop in bone mineralization, with calcium and phosphorus content losses in the femur. In males, deprivation of alimentary calcium shows tangible effects on phosphorus retention only when this situation concurs with prior ingestion of diethylstilbestrol.

A study was made of the Ca and P balance, Ca and P content in the femur, physical characteristics of the egg, mineral structure of the shell, and the number of eggs in quails treated with dieldrin (20 mg/kg of diet) for 48 days. The diet contained 3.24% Ca and 0.72% P. The Ca and P balance, the bone contents of Ca and P and the calcemia in the males were not changed by the pesticide. In the females, the pesticide decreased the amount of excreted Ca and Ca in the egg, for which reason the coefficient of nutritive utilization (CNU), the coefficient of corporal retention (CCR), and the Ca level in the femur were greater in treated laying quails. The calcemia remained stable, and the balance of P was not significantly modified by the dieldrin. The study of weight, size, and strength of the egg did not reveal any influence of the dieldrin, and egg production fluctuated throughout the test period.

Young adult male and laying female quail, fed with a diet containing 2.64% Ca and 0.70% P, were used to study nutritive utilization, corporal calcium retention and endogenous excretion, calcemia, laying and properties of the egg (including the shell structure), mineralization of the femur bone, as well as the influence of diethylstilbestrol upon these parameters. The coefficient of nutritive utilization (C.N.U.) in the female was high and logically superior to that of the male, while the corporal retention was quite similar for both sexes. Most of the Ca absorbed (81.8%) and not excreted in urine, went to the egg and only 18.2% remained in the body. The diethylstilbestrol caused a big reduction of the C.N.U. in the female, but not in the male, parallel to an inhibition of laying, and an increase of corporal retention of used calcium. In both sexes the calcemia surprisingly increased, and the calcium level of the femur bone was higher, and even though the cortical osseous zone was slightly wider, the effect of treatment was noticeable, particularly in the medular tissue, which incremented in the female and appeared in the male. When quail were fed a calcium-restricted diet, the endogenous excretion of this mineral was small in the case of the female and significantly smaller in the male. This situation suppressed egg laying and resulted in a clearly decreased bone mineralization. The ingestion of diethylstilbestrol before feeding a diet poor in calcium provoked an increase of the endogenous excretion of calcium in both female and male quail.

The presence of organochlorated pesticides in foods intended for animal and human consumption is on one hand a real fact and on the other hand, it is known that they could alter some enzymes activities and, consequently, modify, at a larger or lesser extent, the metabolic pathways where they are implicated. According to this, it seemed interesting to study the influence of one of such molecules, dieldrin, on nutrients utilization. The work was carried out on adult quails (Coturnix coturnix japonica) of both sexes; 20 ppm, were mixed in their diets, during a period of 48 days. Dieldrin does not affect food intake in both sexes, but produces a significant weight decrease in the males. Nutritive utilization of protein, judged by digestibility coefficient and nitrogen balance do not suffered any alterations. Furthermore, dieldrin does not affect carbohydrate utilization (nitrogen free extract) and raw fiber. On the contary, fat digestibility decreased in pesticide treated males and was not altered in females and this effect dependend upon the exposition time to the contaminant.