[Relationship between the amount of copper and zinc given to critically ill patients on total parenteral nutrition and plasma and erythrocyte copper and zinc levels]. / Relación entre las cantidades de cobre y zinc administradas a pacientes graves con nutrición parenteral total y los niveles de cobre y zinc en plasma y eritrocitos.

OBJECTIVES: Complications resulting from zinc and copper deficiency, or adverse effects from excessive zinc and copper intake should be avoided during total parenteral nutrition (TPN). This study was conducted on critically ill patients requiring TPN to determine the relationship between the zinc and copper levels of the TPN mixtures, patients' clinical progression, and changes in plasma levels of zinc, serum levels of copper, and erythrocyte levels of zinc and copper. PATIENTS AND METHODS: 29 adult critically ill patients following pancreatitis or after a major abdominal surgery were studied. Zinc and copper levels in TPN, plasmatic zinc levels, copper serum levels and erythrocyte levels of zinc and copper were determined at the onset and at the end of the treatment (5-21 days) (using Atomic Absorption Spectrometry). RESULTS: The mean+/-standard deviation (and ranges in parenthesis) of zinc and copper levels in TPN were (microg/mL): zinc: 4.2+/-1.7 (1.8 a 9.3); copper: 0.94+/-0.66 (0.1 a 3.1). Biochemical parameters at the onset and at the end of the treatment were, respectively: (microg/mL): plasmatic zinc: 80+/-45 (29-205) and 122+/-56 (37-229); erythrocyte zinc: 2,300+/-1,070 (790-5,280) and 2,160+/-920 (790-4,440); serum copper (microg/dL): 124+/-35 (62-211) and 128+/-41 (60- 238); erythrocyte copper (microg/dl): 72+/-39 (4-183) and 70+/-41 (9-156). Plasmatic and erythrocyte zinc levels did not correlated neither at the onset nor at the end of the treatment. Changes in erythrocyte zinc levels correlated with daily administered zinc (mg/d) in the parenteral nutrition (r=0.38). Serum copper and erythrocyte copper showed significant correlation at the onset (p=0.0005) and at the end of treatment (p=0.008). Changes of serum or erythrocyte copper levels showed a significant correlation with daily administered copper (r=0.31 and 0.26, respectively). CONCLUSIONS: These results show that: 1) determination of erythrocyte zinc and copper levels in these critically ill patients would help to control zinc and copper administration levels in TPN and avoid adverse effects; 2) TPN Zn levels should be less than 8.1 mg/d, and 3) TPN Cu levels higher than 1.2 mg/d would not be recommended.

Bone mass changes in vivo during the entire reproductive cycle in rats feeding different dietary calcium and calcium/phosphorus ratio content.

The purpose of this study was to quantify in vivo the impact of different dietary Ca contents on the maternal total skeleton and skeletal sub-areas in adult rats during pregnancy and lactation, using DXA. Twenty-four female Wistar rats (approximately 5 months old) were mated and divided into three groups (n = 8) and fed one of the following diets, varying only in Ca content (LCD: 0.14%, NCD: 0.6% or HCD: 1.2%). Pups were adjusted to 8-9 per dam. Maternal ionic calcium and in vivo bone mineral density (BMD) were measured at the beginning, after delivery and after weaning. Regardless of the diet, ionized calcium decreased from onset to weaning ( P < 0.05). At weaning, bone mass decreased 7.3% in NCD, 15% in LCD and 10.5% in HCD from initial values. Total skeleton, whole and proximal tibia and spine BMDs only decreased at delivery in the LCD group ( P < 0.05) but, irrespective of the diet, at weaning, they were lower compared to delivery and initial values ( P < 0.05). LCD group presented the lowest BMD in the proximal tibia and spine regions ( P < 0.05). At birth, pups did not present differences, however, at weaning, LCD pups reached the lowest body weight ( P < 0.05), NCD presented the highest body Ca content ( P < 0.05) and there were no differences between LCD and HCD. This in vivo study showed that regardless of the dietary calcium content, the maternal skeleton is slightly affected by pregnancy but severely affected by lactation. However, the degree of such response appears to depend not only on dietary Ca content but also on dietary Ca/P molar ratio.

Contenido en algunos nutrientes del alga marina comestible Monostroma undulatum Wittrock de la costa patagónica argentina / Chemical composition and seasonal fluctuations of the edible green seaweed, Monostroma undulatum, Wittrock, from the Southern Argentina coast

The chemical composition of green seaweed, Monostroma undulatum, Wittrock, growing in the Southern Argentina coast, was studied. Samples were collected in Puerto Deseado, province of Santa Cruz (47 degrees 45'L.S., 65 degrees 55'L.W.), from October to December 1999 and 2000. It has been analyzed six sample during this period. Algae were washed with sea water and dried at room temperature for 24 hs. Moisture, nitrogen, lipids and ashes were determined according to AOAC; fiber (total, soluble and insoluble), according to Lahaye. After mineralization with nitric acid, sodium and potassium were determined by flame photometry, calcium by complexometric method, and phosphorus by Gomori's method. The ranges expressed per 100 g dry algae were: protein (Nx6.25): 12.89-21.85; ashes (g): 33.92-40.05; lipid (g): 0.32-1.47; total fiber (g): 14.36-19.6; digestible carbohydrates (calculated by difference) (g): 20.86-32.48; sodium (g): 7.39-13.11; potassium (g): 1.38-3.18; calcium (mg): 149-226; phosphorus (mg): 190-447; Vitamin C (mg): 159-455. These results show that this green seaweed is an important source for protein, fiber, macronutrients minerals and vitamin C, during the macroscopic period. There was an important fluctuation that must be taken into account to consider the commercial collection to use it in human nutrition.