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PubMedDate not supplied

Calcium and phosphorus supplementation after initial hospital discharge in breast-fed infants of less than 1800 grams birth weight.

This study evaluated whether calcium and phosphorus supplementation after initial hospital discharge was advisable in infants of < 1800 gm birth weight who were being breast fed. Twenty-seven infants (15 without any illness affecting nutritional intake and 12 with medical illness) received breast milk plus a liquid human milk fortifier mixed 1:1 and 400 IU vitamin D daily during initial hospitalization. At discharge, 12 infants (6 without and 6 with previous illness) were randomly assigned to receive calcium and phosphorus supplementation, and 15 infants (9 without illness and 6 with previous illness) received no mineral supplementation. A third group of seven healthy infants received a formula for premature infants during initial hospitalization and a standard cow's milk formula (20 calories per ounce) after discharge. The mean plasma calcium, phosphorus, and alkaline phosphatase levels did not differ among the three groups at study entry. Eight weeks after discharge, eight infants (four without illness and four with illness) had hypophosphatemia < 4.5 mg/dl. All were breast fed, and seven of eight had not received posthospitalization calcium and phosphorus supplementation. The incidence of hypophosphatemia in infants with or without illness was significantly greater in infants who did not receive supplementation (p = 0.038). These data indicate that calcium, phosphorus, and vitamin D supplementation may be necessary in approximately 50% of breast-fed infants of < 1800 gm birth weight after hospital discharge. It is recommended that serum calcium, phosphorus, and alkaline phosphatase be measured 4 to 8 weeks after discharge to identify those infants who require supplementation.

Birth Weight↗

PubMedDate not supplied

Hidden phosphorus in popular beverages.

To maintain normal serum phosphorus levels, dialysis patient education has emphasized adherence with phosphate binder prescription and low phosphorus diet. In addition to the standard advice to avoid dairy products and legumes, education also focused on lower phosphorus protein foods and beverages. To meet the public's demands for more high quality convenience food, food-processing practices have stepped up the use of phosphorus additives. These additives are now found in beverages that were once considered low in phosphorus content.

Beverages↗

PubMed1996

Role of Wetlands in Reducing Phosphorus Loading to Surface Water in Eight Watersheds in the Lake Champlain Basin

A landscape-level approach was applied to eight rural watersheds to assess the role that wetlands play in reducing phosphorus loading to surface waters in the Lake Champlain Basin. Variables summarizing various characteristics of wetlands within a watershed were calculated using a geographic information system and then compared to measured phosphorus loading through multiple regression analyses. The inclusion of a variable based on the area of riparian wetlands located along low- and medium-order streams in conjunction with the area of agricultural and nonwetland forested lands explained 88% of the variance in phosphorus loading to surface waters. The best fit model coefficients (Pload=0.86Ag+0.64For-30Ripwet+160) suggest that a hectare of riparian wetland may be many times more important in reducing phosphorus than an agricultural hectare is in producing phosphorus. These results provide additional support for the concept that protection of riparian wetlands is an important management strategy for controlling stream water quality in multiuse landscapes.KEY WORDS: Wetlands; Phosphorus; Landscape; Regression model; Riparian; Vermont

Journal Article↗

PubMed1988

The removal of phosphorus during wastewater treatment: a review.

Phosphorus removal from wastewater can be achieved either through chemical removal, advanced biological treatment or a combination of both. The chemical removal of phosphorus involves the addition of calcium, iron and aluminium salts to achieve phosphorus precipitation by various mechanisms which are discussed. In addition, the effects of operating conditions, especially wastewater characteristics; sludge production in terms of quality and quantity; optimisation of chemical use and re-use; points of chemical addition combined with biological treatment; alternative chemical/physical treatments and examples of full-scale applications are also reviewed. Biological phosphorus removal is dependent upon the uptake of phosphorus in excess of normal bacterial metabolic requirements and is proposed as an alternative to chemical treatment. Early developments and the postulated removal mechanisms are reviewed; these include either natural chemical precipitation, enhanced biological removal, or a combination of both. The nature of excess biological phosphorus removal in activated sludge wastewater treatment plants is evaluated, considering various operating parameters, bacteriology and process designs.

Journal Article↗

PubMed1987

Expression of calbindin-D28K mRNA as a function of altered serum calcium and phosphorus levels in vitamin D-replete chick intestine.

The availability of specific cDNA probes to the chick intestinal calbindin-D28K (CaBP) mRNA has allowed us to assess the regulation of this mRNA in response to 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) administration. It has previously been demonstrated that dietary calcium and phosphorus can effect alterations in the steady-state intestinal levels of chick CaBP. We have examined whether or not perturbations in dietary calcium and phosphorus have an effect on the expression of the intestinal mRNA coding for CaBP in the vitamin D-replete chick. We found altered protein levels of CaBP as expected; however there was surprisingly no difference in steady-state CaBP mRNA levels between the different dietary groups. These data suggest that calcium and phosphorus regulation of CaBP occurs at a post-transcriptional level. In addition, we have examined what effect dietary manipulations of calcium and phosphorus levels have on the response of the vitamin D-replete intestine to 1,25(OH)2D3 administration as assessed by CaBP mRNA changes. Administration of 1,25(OH)2D3 to vitamin D-replete chicks maintained on normal calcium and phosphorus levels resulted in a less than 2-fold increase in CaBP mRNA levels. Previous studies have demonstrated that receptor occupancy goes up 6-fold under these conditions; therefore there is apparently a very tight regulation of CaBP gene activity. 1,25(OH)2D3 administration to chicks raised on either low calcium, high calcium, or low phosphorus vitamin D-replete diets similarly showed only small changes in the intestinal CaBP mRNA levels; however there seemed to be qualitative differences in response attributable to the dietary alterations.

Animals↗

PubMed1996

Phosphorus Chemical Shift Tensors of Phosphole Derivatives Determined by (31)P NMR Spectroscopy of Powder Samples.

The results of a systematic solid-state (31)P NMR study of 5-phenyldibenzophosphole, DBP, its chalcogenides, and some of its transition metal complexes are reported. Phosphorus chemical shift tensors have been obtained from (31)P NMR spectra of stationary samples and of samples spinning about the magic angle. The spans of the phosphorus chemical shift tensors for DBP and its chalcogenides are comparable to those of the corresponding compounds of triphenylphosphine; however, the asymmetry of the tensors for the DBP series reflects the reduced local symmetry at phosphorus. For the complexes (DBP)M(CO)(5) and cis-(DBP)(2)M(CO)(4), where M is a group 6 transition metal (Cr, Mo, W), the most shielded component of the phosphorus shift tensor is found to be relatively independent of the metal or complex, delta(33) = -41 +/- 8 ppm, and is thought to lie along or close to the P-M bond axis direction. In contrast, delta(11) and delta(22) show considerable variation but decrease systematically on descending the group from Cr to W. Group 10 metal complexes, (DBP)(2)MX(2), have also been investigated, including several trans geometric isomers of nickel, cis and trans isomers of palladium, and cis isomers of platinum. The phosphorus shift tensors are nonaxially symmetric with spans in the range 50 -150 ppm. The phosphorus shift tensors of the two nonequivalent DBP ligands of (DBP)(2)PtX(2) (X = Cl, Br) exhibit quite different principal components. The intermediate component of the shift tensor is thought to lie along the Pt-P bond in these complexes. Some of the complexes exhibit interesting MAS-frequency-dependent (31)P NMR spectra.

Journal Article↗

PubMed2005

Poly-p-phenylene phosphine/polyaniline alternating copolymers: electronic delocalization through phosphorus.

Phosphorus-containing poly(N-arylaniline)s and related polymer model compounds have been prepared. The spectroscopic and electronic properties of the materials were investigated via UV-vis-NIR spectroscopy and cyclic voltammetry. PPPP-PANI copolymers containing p-phenylene diamine units in the polymer backbone have electronic and spectroscopic properties characteristic of aromatic substituted p-phenylene diamines. Copolymers containing -(-C(6)H(4)-P-C(6)H(4)-P-C(6)H(4)-)- linkages between nitrogen centers show evidence for weak electronic delocalization along the polymer chain. The electrochemical and spectroscopic properties support strong electronic delocalization in copolymers containing -(-P-C(6)H(4)-N-C(6)H(4)-)- repeat units. The presence of a single diphenylphosphine bridge between nitrogen centers provides an efficient mode of electronic delocalization between nitrogen centers. PPPP oxide-PANI copolymers and related polymer model compounds were also prepared and investigated. The resemblance of PPPP oxide-PANI copolymers to isolated p-phenylene diamines or triarylamines suggests electronic isolation of the amine fragments in the polymer. The conversion of phosphorus(III) phosphines to phosphorus(V) phosphine oxides inhibits electronic delocalization through phosphorus, further supporting delocalization of the lone pair of electrons on phosphorus in PPPP-PANI copolymers. PPPP-PANI copolymers are a new type of pi-conjugated polymer with low oxidation potentials and electronic delocalization through phosphorus along the polymer chain.

Journal Article↗

PubMed2006

Wollastonite as reactive filter medium for sorption of wastewater ammonium and phosphorus.

The utilisation of reactive filter media to remove ammonium and phosphorus can improve the effluent water quality of wastewater treatment systems. The objective of this study was to estimate the ammonium and phosphorus sorption capacity of wollastonite, a calcium meta silicate (CaSiO3) that is distributed worldwide. Phosphorus sorption mechanisms were also investigated. Batch sorption experiments with agitating bottles were carried out and both phosphate and ammonium solutions as well as wastewater were used. The results showed minor ammonium adsorption, with only 3-15% of the ammonium in the solutions being adsorbed to the wollastonite. Neither the reaction time (0.5-20 h) nor the initial concentrations of phosphorus and ammonium (11-114 mg l(-1) NH4-N) were of importance. For high initial phosphate concentrations, phosphate was greatly sorbed to the wollastonite (850 mg kg(-1) at an initial phosphate concentration of 61 mg l(-1) PO4-P). However, phosphate sorption was minor when the initial phosphate concentration was low. This study showed that sorption reactions were important when phosphate was removed by wollastonite, and indicated precipitation of phosphate on the wollastonite surfaces as one possible mechanism for phosphate retention. The results from this study indicated that the wollastonite investigated may not be suitable for municipal wastewater treatment applications due to the low phosphorus sorption capacity for low initial phosphorus concentrations.

Calcium Compounds↗

PubMed1994

Uptake and distribution of calcium and phosphorus in beech (Fagus sylvatica) as influenced by aluminum and nitrogen.

We studied the effects of excess nitrogen added as nitrate (NO(3) (-)) or ammonium (NH(4) (+)), or both, on mineral nutrition and growth of beech (Fagus sylvatica L.) plants grown at pH 4.2 in Al-free nutrient solution or in solutions containing 0.1 or 1.0 mM AlCl(3). A high external concentration of NH(4) (+) increased the concentration of nitrogen in roots, stems and leaves. The root/shoot dry weight ratio was less in plants grown in the presence of NH(4) (+) than in plants grown in the presence of NO(3) (-). The concentration of phosphorus in the roots was increased and the concentration of potassium in all parts of the plant was decreased by NH(4) (+). A high external concentration of NO(3) (-) caused a decrease in phosphorus concentrations of the root, stem and leaf. Uptake of (45)Ca(2+) by roots was reduced in the presence of high concentrations of NH(4) (+) or NO(3) (-), and a combination of high concentrations of nitrogen and aluminum further reduced the uptake of (45)Ca(2+). Uptake of phosphate ((32)P) and concentrations of phosphorus in root and shoot were increased when plants were grown in the presence of 0.1 mM Al. Exposure to 1.0 mM Al, however, reduced the concentration of phosphorus in roots and shoots and the reduction was greater when plants were grown in the presence of a high external NO(3) (-) concentration. Aluminum binds to roots, and plants grown in the presence of 1.0 mM Al had a slightly higher concentration of aluminum in roots than plants grown in the presence of 0.1 mM Al, whereas the concentration of Al in the shoot was increased 2 to 3 times in plants exposed to 1.0 mm Al. Furthermore, the effects of 1.0 mM Al on uptake of other macronutrients were quite different from the effects of 0.1 mM Al. We conclude that 0.1 mM Al facilitates uptake and transport of phosphorus in beech and that between 0.1 and 1.0 mM Al there is a dramatic change in the effects of Al on uptake and transport of divalent cations and phosphorus.

Journal Article↗

PubMed1991

Consequences of rhizosphere acidification on delivery and uptake kinetics of soil phosphorus.

Experiments were undertaken to quantify the mechanisms by which acidity might affect phosphorus movement and uptake by black locust (Robinia pseudoacacia L.). Phosphorus diffusion rates in six forest soils were determined by desorption-isotherm buffer power assays. Changes in diffusion as a function of acidity were measured using pH-adjusted desorption solutions. Depending on soil type and phosphorus source solubility, up to a fivefold increase in phosphorus diffusion rate was observed with an increased acidity of one pH unit. Phosphorus uptake rates of mycorrhizal and non-mycorrhizal black locust at pH 4 and pH 7 were determined from (32)P-labeled nutrient-depletion experiments. In mycorrhizal plants, the rate of phosphorus uptake at pH 4.0 was twice that observed at pH 7.0. Non-mycorrhizal plant uptake rates were similar at both pH 4.0 and pH 7.0. The contribution of soil nutrient supply mechanisms to plant nutrient content increased with rhizosphere acidification. Uptake kinetics were also affected by rhizosphere acidification, but to a lesser extent.

Journal Article↗

PubMed1994

Influence of gadolinium chelates on phosphorus-31 magnetic resonance spectroscopy of the liver.

RATIONALE AND OBJECTIVES: The potential of gadolinium compounds (Gd-ethoxybenzyl-DTPA [Gd-EOB-DTPA], gadopentetate dimeglumine [Gd-DTPA], and Gd-chloride [GdCl3]) to enhance the signals from intracellular phosphorus-31 nuclei in the liver was investigated. METHODS: After intravenous administration of Gd-EOB-DTPA, Gd-DTPA, and GdCl3 to rats, liver phosphorus metabolites (inorganic phosphate [Pi], phosphomonoester [PME], and adenosine triphosphate [ATP]) were measured by phosphorus-31 magnetic resonance spectroscopy (MRS). The dose of each compound was 0.2 mmol Gd/kg. Saline was used as a control. RESULTS: The intensities of the phosphorus metabolite signals in the liver showed only minor changes after administration of Gd-DTPA and GdCl3, but increased after Gd-EOB-DTPA. The signals of Pi and PME were enhanced more than those of ATP. The alpha peak of ATP increased by 21.7%, Pi by 61.2%, and PME by 49.2%. CONCLUSIONS: The signal intensities of the phosphorus metabolites in the liver were not influenced by GdCl3. Using Gd-DTPA, only a slight enhancement could be detected. The greatest enhancement was observed with Gd-EOB-DTPA, which has access to the phosphorus metabolites within the hepatocytes. The injection of Gd-EOB-DTPA results in better detectability of the Pi signal.

Adenosine Triphosphate↗

PubMed1972

Translocation of carbon-14 in sugarcane plants supplied with or deprived of phosphorus.

Translocation of radioactive carbon from the fed part of a blade to the rest of the plant was impaired by a deficiency in phosphorus only when the level of phosphorus was low enough to decrease growth.Phosphorus deficiency decreased the percentage of inorganic phosphorus more than that of organic phosphorus, indicating little effect of phosphorus deficiency upon phosphorylation.Thus phosphorus deficiency did not reduce phosphorylation enough to affect translocation. Evidence for the involvement of phosphorylation in translocation obtained from studies with potassium deficiency, light intensity and quality, 3-(p-chlorophenyl)-1, 1-dimethylurea and 3-(3,4-dichlorophenyl)-1, 1-dimethylurea, and carbon dioxide suggests that noncyclic photosynthetic phosphorylation provides the energy for phototranslocation.

Journal Article↗

PubMed1980

The control of calcium and phosphorus metabolism by the vitamin D endocrine system.

Vitamin D, which is normally produced in the skin under ultraviolet irradiation, is the building block for a new endocrine system that involves hydroxylation on the 25-position in the liver followed by 1 alpha-hydroxylation in the kidney to produce the vitamin D hormone, 1 alpha, 25-(OH)2D3. This vitamin D hormone functions in the intestine, bone, and kidney to stimulate transport of calcium and phosphorus into the extracellular fluid compartment upon demand. The production of the vitamin D hormone is tightly feedback regulated directly or indirectly by calcium and phosphorus levels of the plasma. The vitamin D endocrine system is an important one in the regulation of calcium and phosphorus metabolism but is not solely responsible for the calcium and phosphorus transfer reactions occurring during reproduction. The vitamin D hormone functions in the target organs by a nuclear-mediated receptor-based mechanism probably involving the biogenesis of calcium and phosphorus transfer proteins. New target sites of 1,25-(OH)2D3 action in several tissues are suggested by this nuclear localization in those cells. Study of the vitamin D endocrine system has provided a new understanding of metabolic bone diseases and has provided new forms of vitamin D for their treatment. Thus a basic investigation of the regulation of calcium and phosphorus metabolism has rewarded medicine and science with new therapeutic approaches to disease problems.

25-Hydroxyvitamin D3 1-alpha-Hydroxylase↗

PubMed1994

Culturability and Expression of Outer Membrane Proteins during Carbon, Nitrogen, or Phosphorus Starvation of Pseudomonas fluorescens DF57 and Pseudomonas putida DF14.

Changes in culturability and outer membrane protein profiles were investigated in Pseudomonas fluorescens DF57 and Pseudomonas putida DF14 during starvation for carbon, nitrogen, and phosphorus. P. fluorescens DF57 remained fully culturable for 4 days in all starvation regimes. The cell mass increased during starvation for nitrogen and phosphorus, indicating the accumulation of storage compounds, whereas it decreased slightly in carbon-starved cells. P. putida DF14 lost culturability during phosphorus starvation, and the mass of phosphate-starved cells did not increase. Analysis of additional P. fluorescens and P. putida strains, however, showed that the ability to preserve culturability during phosphorus starvation was not species but strain dependent. In DF57, an outer membrane protein of 55 kDa appeared during starvation for phosphorus, while another protein of 63 kDa was seen during all starvation conditions. DF14 induced two outer membrane proteins of 28 and 29 kDa during starvation for carbon and nitrogen, but no phosphorus-specific starvation protein could be detected. Therefore, starvation-induced outer membrane proteins do not seem to be conserved among the fluorescent pseudomonads and a unique starvation response might be found in individual strains.

Journal Article↗

PubMed1989

Relationship between the uptake of calcium or phosphorus and alkaline phosphatase activity induced by certain modulators in rat organs.

The effects of phorbol ester or calmodulin on the calcium and phosphorus uptakes by rat tissues and their relationship to the alkaline phosphatase activity (ALP) were investigated in vivo. In rat tissues, ALP activity and calcium uptake in the duodenum and liver were clearly induced by phorbol ester treatment, whereas in the calvarium and ileum they were decreased. Phosphorus uptake was increased by the administration of phorbol ester only in the calvarium. In rats pretreated with an injection of indomethacin as an inhibitor of prostaglandin-synthesizing enzyme, the selective uptake of calcium by phorbol ester was eliminated in the duodenum and liver, as was the ALP activity. In contrast, rats showed a marked increase in ALP activity in the ileum after calmodulin treatment. Moreover, the increased uptake of calcium after calmodulin treatment was clearly seen in the ileum, calvarium, and kidney, and an increased uptake in phosphorus was seen in the duodenum, ileum, and calvarium, but not in kidney. Furthermore, prior injection of W-7 or calmidazolium as an antagonist of calmodulin, reduced the increased ALP activities and the uptake of calcium in all organs tested, but did not reduce the increased phosphorus uptake by the calvarium. Consequently, it is suggested that calcium uptake under the above conditions correlated well with changes in the ALP activity; however, phosphorus uptake seemed to be less in accord with ALP activity. The amount of tested other mineral metabolic markers suggests that the Ca uptake and ALP activity induced by certain effectors regulate 1,25(OH)2D3 level by the modulation of 25(OH)D3-1 alpha-hydroxylase activity.

Alkaline Phosphatase↗

PubMed1996

The effect of estrogen deficiency on bone mineral density, renal calcium and phosphorus handling and calcitropic hormones in the rat.

The oophorectomized (OOX) rat has been proposed as a good model of postmenopausal osteoporosis in women. The aim of this study was to compare the effect of OOX in 6-month-old rats to the effects of menopause in women with respect to bone mass, the renal handling of calcium and phosphorus, and calcitropic hormones. To more closely replicate the human situation the rats were pair fed a 0.1% calcium diet. Thirty four, 6-month-old rats were randomized to sham operation or OOX. Whole body and regional bone density was performed at baseline and 6 weeks postoperation. Blood and 24-hour urine samples were obtained at baseline, 1, 3, and 6 weeks and assayed for various biochemical variables, parathyroid hormone (PTH), and calcitriol. The OOX rats lost significantly more bone than the sham-operated rats (change in global bone mineral density, sham -1.7 +/- 2.0%, OOX -3.9 +/- 2.6%, P < 0.001). In the OOX animals, an increase in the 24-hour urine calcium was observed at 1 and 3 weeks, which had returned to sham-operated levels by 6 weeks. In the whole group, the increase in urine calcium at 1 week was negatively correlated with the change in bone mass at 6 weeks (r = -0.39, P = 0. 029). OOX resulted in an increased filtered load of calcium and phosphorus. There was an increase in the maximal renal tubular reabsorption of phosphorus (TmP-GFR) but no clear change in renal calcium handling. Neither calcitriol nor parathyroid hormone showed a significant change as a result of OOX. As in postmenopausal women, following oophorectomy in the rat, there was significant generalized bone loss and a negative calcium balance. This was associated with an initial rise in urine calcium due to a rise in the filtered calcium load; plasma phosphorus and TmP-GFR also rose. The rat model may differ from postmenopausal bone loss in that the initial rise in urine calcium was not present at later time points as occurs in natural menopause in women. Calcitropic hormone levels did not change. This study has shown that the 6-month-old OOX rat fed a 0.1% calcium diet has many similarities of calcium and phosphorus homeostasis to that seen at menopause in women.

Absorptiometry, Photon↗

PubMed2005

Calcium and phosphorus metabolism in patients who have chronic kidney disease.

Disturbances in calcium and phosphorus metabolism are almost invariable consequences of chronic kidney disease (CKD). Because the capacity to regulate calcium and phosphorus metabolism becomes compromised progressively as kidney function declines, calcium and phosphorus homeostasis is disrupted and serum calcium or phosphorus levels are perturbed in many patients with CKD. The level of interest in, and concerns about, abnormalities in calcium and phosphorus metabolism among patients with CKD has increased substantially in recent years. Strategies for clinical management are being revised, and recent recommendations differ substantially from those used previously with a renewed emphasis on safety.

Calcium↗

PubMed1996

Phosphorus accelerates the development of parathyroid hyperplasia and secondary hyperparathyroidism in rats with renal failure.

Several studies have suggested that phosphorus (P) restriction, independent of serum levels of ionized calcium and 1,25-(OH)2D3, may prevent parathyroid hyperplasia and secondary hyperparathyroidism in patients and animals with chronic renal failure. A direct role of phosphorus in the pathogenesis of these abnormalities is, however, still controversial. Thus, studies were performed to examine the direct role of phosphorus on the development of these abnormalities. Female Sprague-Dawley rats underwent 5/6 nephrectomy or sham operation. The animals were then divided into two dietary groups (High-P: 0.8% P diet, Low-P: 0.2% P diet). Six to eight rats per group per time-point were killed at the following intervals: 0, 1, 2, and 4 days, and 1, 2, 3, and 4 weeks. Serum intact parathyroid hormone (PTH) levels in uremic rats fed the high-P diet increased 1 day after nephrectomy, and high levels persisted for the duration of the study. Parathyroid gland growth in uremic rats fed the high-P diet was apparent within 2 days of uremia and increased nearly twofold by 2 weeks. These abnormalities, however, did not develop in uremic rats fed the low-P diet. Serum P levels in uremic rats fed the high-P diet were significantly higher than those of uremic rats fed the low-P diet, but there was no significant difference in serum ionized calcium or 1,25-(OH)2D3 levels. These results demonstrate that phosphorus accelerates the development of parathyroid hyperplasia and secondary hyperparathyroidism in rats with renal failure, and that phosphorus restriction prevents these abnormalities independent of changes in serum ionized calcium and 1,25-(OH)2D3.

Animals↗