Essential trace element provision to patients receiving home intravenous nutrition in the United Kingdom

An Edible and Nutritive Zinc-Ion Micro-supercapacitor in the Stomach with Ultrahigh Energy Density

Miniature energy storage devices simultaneously combining high energy output and bioavailability could greatly promote the practicability of green, safe, and nontoxic in vivo detection, such as for noninvasive monitoring or treatment in the gastrointestinal tract, which is still challenging. Herein, we report ingestible and nutritive zinc-ion-based hybrid micro-supercapacitors (ZMSCs) consisting of an edible active carbon microcathode and zinc microanode, which can be inserted into a standard-sized capsule and ingested in a pig stomach. With features including flexibility, light weight, and shape adaptability, a single microdevice displays a high energy density of 215.1 μWh cm^-2, superior to that of state-of-the-art biocompatible SCs/MSCs and even traditional ZMSCs reported previously. It also delivers an areal capacitance of 605 mF cm^-2 and a high working voltage of 1.8 V, exceeding that of miniaturized commercial button batteries (1.55 V, RENATA 337). Comprehensive studies in vivo and in vitro demonstrate that the ZMSCs with high biocompatibility and safety not only power electronic equipment in the porcine stomach without a voltage booster but also act as a nutritional supplement of trace element zinc within the dose range, as well as the ability of potent antibacterial activity against bacterium Escherichia coli during the discharging process. This work provides an example for the design and fabrication of edible energy storage devices with high performance.

Selenium losses in 10 burned patients

To determine the selenium (Se) losses and balances, 10 patients with burns of 32 +/- 9% (mean +/- SD) of total body surface and aged 36 +/- 9 years were studied from D1 (first post-injury) unitl D7. Cutaneous losses were extracted from the textiles surrounding the patients. Serum and urine were collected until D20. Exudative losses of nitrogen decreased progressively (mean 8.7 +/- 3.8 g/24H). Se was detectable in wound seepage only during excision-grafting: mean operative loss was 342 +/- 191 mug. Mean urinary Se excretion was 41 +/- 13 mug/24H. Operative cutaneous losses led to some negative balances. Serum Se and glutathione peroxydase (GSHPx) were depressed until D20. Serum Se was related to N intake (p < 0.001). The decreased Se and GSHPx levels reflect a deficiency state, which measured losses did not explain, but limitations of the measurement methods prevented detection of Se cutaneous losses 100 mug/24H.

Selenium levels in related biological samples: human placenta, maternal and umbilical cord blood, hair and nails

A study on selenium levels has been carried out in human placenta, maternal and umbilical cord blood, hair and nails of a group of 50 mothers and in the hair of the newborns. The determinations were perfomed by electrothermal atomic absorption spectrometry. The selenium concentration obtained for each sample type was as follows: For the human placenta the values obtained were between 0.56 and 1.06 microg/g (mean +/- standard deviation: 0.81 +/- 0.02 microg/g). The levels for the umbilical cord blood were 51.1-104.2 microg/l (76.3 +/- 6.5 microg/l). For the maternal blood the values measured were between 57.3 and 117.9 microg/l (90.0 +/- 15.2 microg/l), and for hair and nails were 0.22-1.5 microg/g (0.60 +/- 0.37 microg/g) and 0.46-1.57 microg/g (0.90 +/- 0.27 microg/g), respectively. For the hair of the newborns the values obtained were between 0.40 and 2.53 microg/g (1.04 +/- 0.48 microg/g). The effect of different variables as age, habitat, nutritional index or gestation age of the mothers on the selenium concentration in the samples was studied. The influence of the habitat is significant with a confidence level of 95% for the selenium concentration in maternal blood and umbilical cord blood samples. The influence of the mothers' age is significant with a confidence level of 95% for the selenium concentration in the umbilical cord blood samples. For the placenta samples, the effect of the nutritional index is significant with a confidence level of 95%. There is a positive correlation between samples of umbilical cord blood and the newborns' hair, between placenta and umbilical cord, and between cord blood and maternal blood.

Management of patients with a short bowel

There are two common types of adult patient with a short bowel, those with jejunum in continuity with a functioning colon and those with a jejunostomy. Both groups have potential problems of undernutrition, but this is a greater problem in those without a colon, as they do not derive energy from anaerobic bacterial fermentation of carbohydrate to short chain fatty acids in the colon. Patients with a jejunostomy have major problems of dehydration, sodium and magnesium depletion all due to a large volume of stomal output. Both types of patient have lost at least 60 cm of terminal ileum and so will become deficient of vitamin B₁₂. Both groups have a high prevalence of gallstones (45%) resulting from periods of biliary stasis. Patients with a retained colon have a 25% chance of developing calcium oxalate renal stones and they may have problems with D (-) lactic acidosis. The survival of patients with a short bowel, even if they need long-term parenteral nutrition, is good.

Micronutrients in the severely-injured patient

The trace element and vitamin requirements of severely-ill injured patients depend on a complex interaction of the status of the patient at the time of admission, ongoing losses and the potential benefit of supplying large amounts of individual micronutrients. Characteristic clinical deficiency states are now uncommon, but subclinical deficiency is of growing concern. The main effects of subclinical deficiency are: (1) an altered balance of reactive oxygen species and antioxidants, leading to oxidative damage of polyunsaturated fatty acids and nucleic acids, and possibly to increased activation of the transcription factor nuclear factor-kappaB, with increased production of pro-inflammatory cytokines: (2) impaired immune function with increased likelihood of infectious complications. Laboratory tests to optimize intake in such critically-ill patients lack sensitivity and specificity, this situation being made worse as a result of the acute-phase response. Recent studies have indicated the clinical benefit of providing large amounts of certain micronutrients in burned and head-injured patients. Further clinical studies are now required to define optimal levels of provision in different disease states, with a particular emphasis on markers of tissue function and clinical outcome.

Selenium determination in mother and child's hair by electrothermal atomic absorption spectrometry

A method for the selenium determination in a mother and her child's hair using palladium as a chemical modifier was optimized. The sample was digested with nitric acid and hydrogen peroxide and diluted to 5 ml. To achieve complete mineralization the samples were ashed at 1200 degrees C in the presence of palladium as a chemical modifier. The optimum atomization temperature was 1900 degrees C. The precision and accuracy of the method were studied using the reference material CRM 397. Results of calibration using aqueous standards and the standard addition method were compared. The method was applied to the selenium determination in 30 samples of the mother's and child's hair. The levels found were 0.54 +/- 0.34 microgram/g for mother's hair and 0.77 +/- 0.25 microgram/g for child's hair.

Micronutrients and outcome

Micronutrient deficiency not only causes symptoms of severe deficiency, but may also cause more subtle effects on tissue function, including immune deficiency and oxidative damage. The duration of a deficiency state, which is necessary before such effects are clinically significant, is not known. Most biochemical tests are relatively insensitive in detecting changes in micronutrient status, although they do provide a crude index. Many tests are nonspecific, being affected by the acute phase response as well as by nutritional status. Cellular tests are more sensitive and specific than tests in plasma. When interpreted carefully in association with the knowledge of the patient's clinical condition and nutritional intake, laboratory tests can be helpful in diagnosing deficiency states or conditions of excess provision, and in monitoring progress. Well conducted clinical trials of micronutrients in nutritional support are beginning to appear in the literature. Further studies are urgently required that relate outcome to levels of provision and biochemical indices of nutrient status.

Analysis of selenium in bovine liver by gas chromatography with mass-selective, electron-capture and nitrogen-phosphorus detection

The concentration of selenium (Se) in liver was determined by gas chromatography (GC) with mass-selective (GC-MS), electron capture (GC-ECD) and nitrogen-phosphorus (GC-NPD) detection. Liver samples were digested in a mixture containing HNO3 and Mg(NO3). SeVI was converted to SeIV. SeIV was derivatized with 4-nitrophenylenediamine and then extracted in toluene. A 1-microliter volume of the toluene extract was analyzed by the GC-MS, GC-ECD or GC-NPD methods. The detection limits of the GC-ECD, the GC-NPD and the GC-MS methods were 25, 50 and 800 pg, respectively. The GC-NPD method was more selective for the derivatized Se than the GC-ECD method. The GC-MS method had the advantage of using the 76Se isotope as the internal standard. Se concentrations in liver samples determined by the three methods were comparable.

Can elevated chromium induce somatopsychic responses?

The possible somatopsychological effects of chromium (Cr) was investigated in a population of patients, from a surgical ward of our hospital, who required total parenteral nutrition (TPN) solutions, and who became exposed to various amounts of this metal from this treatment. The study involved a questionnaire as well as biochemical tests which included serum Cr and other selected trace metals. The renal status for all eligible patients was within normal parameters. The patient population varied in age, pathology, surgical treatment, and duration on TPN. The results showed that every patient who received TPN had an increased serum Cr level; some increases were up to 50-fold above the normal reference level for serum Cr. Although statistical analysis failed to show any significant statistical relationship between an increased serum Cr and the investigated somatopsychological disturbances, this effect cannot be ruled out since one case did show all the dream disturbances. Considering these cases, the action of sedative medications that may suppress the effects of Cr, cannot be ruled out. As Cr(III) may be potentially genotoxic at high concentrations, infusion of this metal over long time periods should be avoided. Supplementation of Cr in TPN solutions appears to be unnecessary for short-term TPN because this metal is a known contaminant of these solutions. Efforts are required to find TPN nutrients with low or no Cr contamination.

Trace elements in parenteral micronutrition

OBJECTIVE

To update some essential trace metals required in total parenteral nutrition.

CONCLUSION

Essential trace metals, chromium, copper, manganese, molybdenum, selenium, and zinc are added to parenteral fluids to prevent the development of deficiency syndromes. When possible, these metals should be monitored, even in patients on short-term total parenteral nutrition (TPN) to avoid deficiency or toxicity. Many of the nutrients or additives used in parenteral solutions may be contaminated with metals, such as aluminum or chromium. Such trace-metal monitoring becomes more critical in infants, and those on long-term TPN.

The necessity of selenium substitution in total parenteral nutrition and artificial alimentation

For the trace element selenium, in contrast to zinc, iron, copper, chromium, manganese and iodine, there is still no clear official recommendation with regard to routine substitution in artificial nutrition. An overview of the manifestations of selenium deficiency in humans during the period 1979-1995 shows that nutritive deficiencies are exclusively TPN-induced or the result of severe malnutrition. The pathology of TPN-induced selenium deficiency and the analytic assessment of selenium status are described. Patients undergoing long-term parenteral nutrition or suffering from an increased loss of intestinal secretions have to be characterized as being especially at risk for clinical selenium deficiency. The relationship of the serum selenium kinetics in pediatric and adult patients to the depletion of body compartments during the course of short-term and prolonged TPN is discussed. Because of the importance of the selenoproteins, the regularly occurring depletion during selenium-free TPN and the borderline supply of selenium in Germany the routine substitution of selenium in TPN is strongly recommended. The pharmaceutical industry should be encouraged to develop a trace element solution that includes selenium, so that the nutritive requirement of patients on TPN can be satisfied. Adequate intravenous dosage recommendations are based on maintenance of glutathione peroxidase homeostasis. The routine supplementation dosage may not meet the selenium requirements of intensive care patients under conditions of increased metabolic demands on their anti-oxidative system.

Clinical effects and adequacy of a new all-in-one dextrose-electrolyte-trace element preparation in patients on prolonged TPN

We have devised a new all-in-one dextrose/electrolyste/trace element mixture (Polyfusor DY) and tested its efficacy in clinical practice. Polyfusor DY was designed to be combined with an amino-acid preparation and to be infused with lipid in a standard total parenteral nutrition (TPN) regimen. This standard regimen was formulated to provide minimum nitrogen, energy, fluid, electrolyte, vitamin and trace element requirements for the stable patient. The adequacy of currently recommended levels of provision of trace elements was tested in patients receiving long periods of intravenous nutrition. Eleven consecutive patients were fed from 13 to 280 days using TPN prescriptions based on this standard regimen. Two patients died but the nutritional state of the remainder improved. Serum concentrations of zinc, copper, chromium and manganese remained largely within or above the reference ranges, however the selenium content of Polyfusor DY (500 nmol/l) was marginally inadequate to maintain normal biochemistry. Pharmacy compounding time for the standard TPN regimen based on Polyfusor DY was 10.6 +/- 0.19 min (mean +/- SEM) compared with 22.5 +/- 0.30 min for non-standard TPN regimens prescribed independently by other clinicians (P < 0.001). A standard TPN regimen based on Polyfusor DY was clinically effective, in particular giving generally adequate trace element provision with a reduction in pharmacy time and costs.

Clinical aspects of vitamin and trace element metabolism

An adequate provision of all micronutrients, vitamins and essential trace elements is necessary for maintenance of normal tissue function. In patients requiring nutritional support, these factors are essential for optimal utilization of the major nutrients and play a role in all aspects of intermediary metabolism. In this chapter, some of the main features of the micronutrients have been described, together with suggestions regarding their provision enterally or parenterally. For most of these nutrients, diagnostic methods are not available to permit accurate assessment of status and hence the level of provision necessary for optimal results. However, there is now sufficient understanding of nutritional requirements such that few patients should now develop clinical or biochemical signs of under- or overprovision of micronutrients.

Maintenance of vitamin and trace element status in intravenous nutrition using a complete nutritive mixture

Complete nutritive mixtures (CNM) of all intravenous nutrients including fat emulsions are being used increasingly because of their convenience. However, this may lead to chemical interactions and reduce the amount of active vitamins and trace elements made available to the patient. We have studied the effects on micronutrient status of provision of all nutrients in one 3-liter bag (CNM: amino acids, dextrose, Intralipid 20%, a nine-element trace metal mixture, and complete fat- and water-soluble vitamin mixtures) in 10 postoperative surgical patients [median intravenous nutrition (IVN) 14.5 days, range 7-38]. A similar group received the fat emulsion plus water- and fat-soluble vitamins as a separate infusion (SI) from a 3-liter bag (median IVN 14.0 days, range 8-28). Serum and urine magnesium, zinc, copper, manganese, chromium, and selenium, serum vitamins A, E, C, folate, and B12, RBC B1, B2 B6, and folate and leukocyte vitamin C were measured at weekly intervals. All patients in both groups maintained or improved their status for all the micronutrients analyzed. No significant differences between the CNM and SI groups were found in blood concentrations of any of the elements or vitamins. Only for urine copper did the CNM lead to increased excretion (1.51 +/- 0.59 mumol/24 hr; copper input 20 mumol/day), compared to SI (1.00 +/- 0.70 mumol/day, p less than 0.001 Mann-Whitney test) suggesting possible interaction. It is concluded that micronutrient status was maintained during short-term IVN with the CNM and that it did not lead to a significantly greater loss of vitamins or essential trace elements than the SI system.