High Chloride Levels Research Articles

Treatment of rising damp and salt decay: the historic masonry buildings of Adelaide, South Australia

The City of Adelaide suffers from rapid damage to historic building materials due to salts, rising damp, and damp-proof course failures. Adelaide City Council has partially funded repairs to over 400 buildings in the past 15 years. To begin to examine the scope of this problem and the effectiveness of various treatments, 24 historic buildings in Adelaide were examined, with a focus on the building materials, historic interventions and current treatments applied to treat rising damp and salt decay. Analysis of 90 samples found high levels of sodium sulfate, sodium chloride and sodium nitrate in cellars, ground water and building materials, suggesting a clear example of rising damp. Samples of disintegrating masonry, depth profiles acquired by drilling, poultices and damp proof courses (DPC) were analyzed by Ion Chromatography (IC) and Environmental Scanning Electron Microscopy coupled with Energy Dispersive Spectroscopy (ESEM/EDS). Mercury Intrusion Porosimetry (MIP) and capillarity test were carried out in the building materials and DPCs showing that porous materials with high porosity, small pores and low strength are more prone to salt weathering. The City of Adelaide is a natural laboratory for comparing and analyzing different treatments of salt-laden masonry, with hundreds of treated buildings of the same age, in the same environment, and with similar building materials.

Responses of aquatic organisms to metal pollution in a lowland river in Flanders: A comparison of diatoms and macroinvertebrates

The role of macroinvertebrates and diatoms as indicator for metal pollution was investigated by assessing both biota along a metal gradient in the Belgian river the Dommel. Macroinvertebrates and diatoms were sampled in summer and winter and physical–chemical characteristics of the water were measured at four different sample periods and related to sediment characteristics. Although metal concentrations, except cadmium, in the water nowhere exceeded water quality standards, high metal concentrations were measured in the sediment, indicating historical contamination of the Dommel. At the sites that were situated downstream of the pollution source, high levels of conductivity and chloride were measured in the water. Redundancy Analysis (RDA) indicated pH, phosphate and zinc as the significant environmental variables explaining each respectively 7.7%, 11.6% and 22.6% of the macroinvertebrate community composition. Two clusters could be separated, with Gammarus pulex, Leptocerus interruptus, Baetis rhodani and Cloeon dipterum associated with low zinc concentrations and Tubificidae, Asellus aquaticus, Erpobdella sp. and Chironomus thummi-plumosus associated with higher zinc concentrations. Ammonium (10.6%), conductivity (16.5%), chloride (11.4%) and zinc (5.9%) turned out to be significant variables explaining the diatom community structure. Based on physical–chemical differences and species composition, three different groups could be separated. With this Tabellaria flocculosa and Fragilaria capucina var. rumpens were associated with low metal concentrations, Gomphonema parvulum and Nitzschia palea with elevated concentrations and Eolimna minima and Sellaphora seminulum with high zinc concentrations. In conclusion, the diatom community best reflected the metal gradient. With regard to water quality indices, those based on macroinvertebrates best followed the metal pollution gradient and were most strongly correlated with physical–chemical variables of water and sediment. This study indicated that to assess the effect of metal pollution in lowland rivers, the combined use of macroinvertebrates and diatoms is more appropriate than the use of both biota separately.

Standardized Sweat Chloride Analysis for the Diagnosis of Cystic Fibrosis in Korea

Cystic fibrosis is a chronic progressive autosomal recessive disorder caused by the CFTR gene mutations. It is quite common in Caucasians, but very rare in Asians. Sweat chloride test is known to be a screening test for the cystic fibrosis due to the fact that electrolyte levels in sweat are elevated in patients. In this study, sweat chloride levels in Korean population were measured and analyzed by using standardized pilocarpine iontophoresis sweat chloride test. The sweat chloride test was performed in 47 patients referred to Yondong Severance Hospital from August, 2001 to April, 2007 and 41 healthy volunteers. The sweat chloride tests were conducted according to the CLSI C34-A2 guideline using pilocarpine iontophoresis method, and the chloride concentrations in sweat were measured by mercurimetric titration. Four patients showed sweat chloride concentrations higher than 60 mmol/L. Reference interval was calculated as 1.4-44.5 mmol/L by analysis of the results of healthy volunteers (n=41). Four patients who exhibited high sweat chloride levels, had characteristic clinical features of cystic fibrosis and their diagnoses were confirmed either by repeated sweat chloride test or genetic analysis. Standardized sweat chloride test can be utilized as a useful diagnostic tool for cystic fibrosis in Koreans. In cases of sweat chloride levels higher than 40 mmol/L, the test should be repeated for the possible diagnosis of cystic fibrosis. All the confirmed Korean cases of cystic fibrosis showed sweat chloride level above 60 mmol/L.

Abstracts from the Association of British Clinical Diabetologists (ABCD) meetings

Abstracts from the Association of British Clinical Diabetologists (ABCD) meetings

Coincident pre‐ and postsynaptic activity downregulates NKCC1 to hyperpolarize ECl during development

In the mature CNS, coincident pre- and postsynaptic activity decreases the strength of gamma-aminobutyric acid (GABA)(A)-mediated inhibition through a Ca2+-dependent decrease in the activity of the neuron-specific K+-Cl- cotransporter KCC2. In the present study we examined whether coincident pre- and postsynaptic activity can also modulate immature GABAergic synapses, where the Na+-K+-2Cl- (NKCC1) cotransporter maintains a relatively high level of intracellular chloride ([Cl-](i)). Dual perforated patch-clamp recordings were made from cultured hippocampal neurons prepared from embryonic Sprague-Dawley rats. These recordings were used to identify GABAergic synapses where the reversal potential for Cl- (ECl) was hyperpolarized with respect to the action potential threshold but depolarized with respect to the resting membrane potential. At these synapses, repetitive postsynaptic spiking within +/- 5 ms of GABAergic synaptic transmission resulted in a hyperpolarizing shift of ECl by 10.03 +/- 1.64 mV, increasing the strength of synaptic inhibition. Blocking the inward transport of Cl- by NKCC1 with bumetanide (10 microm) hyperpolarized ECl by 16.14 +/- 4.8 mV, and prevented this coincident activity-induced shift of ECl. The bumetanide-induced hyperpolarization of ECl occluded furosemide, a K+-Cl- cotransporter antagonist, from producing further shifts in ECl. Together, this indicates that brief coincident pre- and postsynaptic activity strengthens inhibition through a regulation of NKCC1. This study further demonstrates ionic plasticity as a mechanism underlying inhibitory synaptic plasticity.

High levels of nitryl chloride in the polluted subtropical marine boundary layer

Nitryl chloride, an active halogen, can be produced through the night-time reaction of dinitrogen pentoxide with chloride-containing aerosol in the polluted marine boundary, and has been measured at levels that are sufficient to affect the photochemistry of oxidants off the southwestern US coast and near Houston, Texas.

Hypokalemia as the principal symptom of covert vomiting. Clinical and diagnostic aspects

In ten adults (nine females), referred for hypokalemia as the cardinal symptom of uncertain etiology and normal blood pressure, surreptitious self-induced vomiting was demonstrated as the main cause. In the majority of such patients, the pathognomonic pattern of serum and urine electrolytes (in the unstable phase--loss of gastric juice) allows diagnosis without hospitalization. If there are atypical urinary electrolyte values or the patients deny vomiting, hospitalization or part-hospitalization is recommended, with parenteral administration of 1 litre physiological saline daily under weight control, and (if necessary) toxicological urine tests for diuretics if there is a high urinary chloride level. In this manner a sufficiently accurate diagnosis is possible.

Geochemistry and toxicity of sediment porewater in a salt-impacted urban stormwater detention pond

A comprehensive study was carried out to investigate the impacts of road salts on the benthic compartment of a small urban detention facility, Rouge River Pond. Although the pond is an engineered water body, it is representative of many small urban lakes, ponds and wetlands, which receive road runoff and are probable high impact areas. Specific objectives of the study were to document the porewater chemistry of an aquatic system affected by elevated salt concentrations and to carry out a toxicological assessment of sediment porewater to determine what factors may cause porewater toxicity. The results indicate that the sediment porewater may itself attain high salt concentrations. The computations show that increased chloride levels have important implications on the Cd complexation, augmenting its concentration in porewater. The toxicity tests suggest that the toxicity in porewater is caused by metals or other toxic chemicals, rather than high levels of chloride.

Chloride Movements in Human Neutrophils during Phagocytosis: Characterization and Relationship to Granule Release

Chloride ion efflux is an early event occurring after exposure of human neutrophils to several soluble agonists. Under these circumstances, a rapid and reversible fall in the high basal intracellular chloride (Cl-i) levels is observed. This event is thought to play a crucial role in the modulation of several critical neutrophil responses including activation and up-regulation of adhesion molecules, cell attachment and spreading, cytoplasmic alkalinization, and activation of the respiratory burst. At present, however, no data are available on chloride ion movements during neutrophil phagocytosis. In this study, we provide evidence that phagocytosis of Candida albicans opsonized with either whole serum, complement-derived opsonins, or purified human IgG elicits an early and long-lasting Cl- efflux accompanied by a marked, irreversible loss of Cl-i. Simultaneous assessment of Cl- efflux and phagocytosis in cytochalasin D-treated neutrophils indicated that Cl- efflux occurs without particle ingestion. These results suggest that engagement of immune receptors is sufficient to promote chloride ion movements. Several structurally unrelated chloride channel blockers inhibited phagocytosis-induced Cl- efflux as well as the release of azurophilic-but not specific-granules. It implicates that different neutrophil secretory compartments display distinct sensitivity to Cl-i modifications. Intriguingly, inhibitors of Cl- exchange inhibited cytosolic Ca2+ elevation, whereas Cl- efflux was not impaired in Ca2+-depleted neutrophils. We also show that FcgammaR(s)- and CR3/CR1-mediated Cl- efflux appears to be dependent on protein tyrosine phosphorylation but independent of PI3K and phospholipase C activation.

Clinical Challenges and Images in GI

Clinical Challenges and Images in GI

Rust Layer Structure and Corrosion Resistance of High Strength Microalloyed Steels

Corrosion behavior and corrosion resistance of two laboratory prepared microalloyed steels (steel 1 and steel 2) and a commercial traditional weathering steel (TWS) was compared. All these steels contain 0.03% C, 0.50% Si, 1.35%Mn, 0.30%Mo, 0.030Nb, 0.35%Cu%, 0.30%Ni and 0.040%Ti. In addition, steel 1 contains 0.0028%B, steel 2 contains 0.0026%B, 0.66%Cr, TWS contains 0.63%Cr. It has been found that a noticeable change occurs in optical microstructures attributed to a very little amount of boron. The mechanical properties of steel 2 are much better than that of TWS. The corrosion behavior of the three steels has been investigated by an alternating wet-dry experiment. Small amount of pearlite appears in TWS, which lead to its higher corrosion rate. The corrosion depth of steel 2 is nearly thrice that of steel 1. The compound components of inner rust in steel 1 and steel 2 are similar. The Nyquist diagrams indicate that the corrosion rate of steel 1 is controlled by the diffusion of oxygen in rust layer while it in steel 2 is controlled by chemical reaction in rust, which result in loosened rust layer and higher corrosion rate to steel 2. Addition of chromium cannot enhance the corrosion resistance of steel, but reduce the corrosion resistance in environments with high levels of chlorides.

Advanced oxidation of bleached eucalypt kraft pulp mill effluent

In this study a poorly biodegradable (BOD/COD = 0.3) industrial alkaline ECF bleaching filtrate was treated using different advanced oxidation processes to evaluate their use in combined chemical-biological treatment aimed at increasing recalcitrant COD removal and improving final effluent quality. Oxidative treatments included ozonation combined with hydrogen peroxide (2, 5, 10, 20 mmol L(-1) O3/0.7, 2, 5, 10 mmol L(-1) H2O2) and photocatalysis with hydrogen peroxide (UV/2, 4 and 8 mmolL(-1) H2O2) and with TiO2 (UV/TiO2/0.7 and 4 mmol L(-1) H2O2). The O3/H2O2 process increased effluent biodegradability by up to 68% as a result of increasing BOD and decreasing COD. Increasing the O3 dose had a greater effect on biodegradability improvement and lignin and colour removal efficiencies than increasing the H2O2 dose. A combined oxidant dose of 5 mmol L(-1) O3 and 2 mmol L(-1) H2O2 resulted in 75% lignin removal, 40% colour removal and 6% carbohydrate loss without mineralizing the organic carbon. The photocatalytic processes led to a decrease in effluent biodegradability through combined decrease in BOD and increase in COD and did not result in efficient lignin or colour removal. Photocatalytic oxidation was apparently inhibited by the high chloride and COD levels in the alkaline filtrate, and may be more efficient in recalcitrant COD removal if performed after biological.

Simulating the effects of saline and sodic subsoils on wheat crops growing on Vertosols

Soils with high levels of chloride and/or sodium in their subsurface layers are often referred to as having subsoil constraints (SSCs). There is growing evidence that SSCs affect wheat yields by increasing the lower limit of a crop’s available soil water (CLL) and thus reducing the soil’s plant-available water capacity (PAWC). This proposal was tested by simulation of 33 farmers’ paddocks in south-western Queensland and north-western New South Wales. The simulated results accounted for 79% of observed variation in grain yield, with a root mean squared deviation (RMSD) of 0.50 t/ha. This result was as close as any achieved from sites without SSCs, thus providing strong support for the proposed mechanism that SSCs affect wheat yields by increasing the CLL and thus reducing the soil’s PAWC. In order to reduce the need to measure CLL of every paddock or management zone, two additional approaches to simulating the effects of SSCs were tested. In the first approach the CLL of soils was predicted from the 0.3–0.5 m soil layer, which was taken as the reference CLL of a soil regardless of its level of SSCs, while the CLL values of soil layers below 0.5 m depth were calculated as a function of these soils’ 0.3–0.5 m CLL values as well as of soil depth plus one of the SSC indices EC, Cl, ESP, or Na. The best estimates of subsoil CLL values were obtained when the effects of SSCs were described by an ESP-dependent function. In the second approach, depth-dependent CLL values were also derived from the CLL values of the 0.3–0.5 m soil layer. However, instead of using SSC indices to further modify CLL, the default values of the water-extraction coefficient (kl) of each depth layer were modified as a function of the SSC indices. The strength of this approach was evaluated on the basis of correlation of observed and simulated grain yields. In this approach the best estimates were obtained when the default kl values were multiplied by a Cl-determined function. The kl approach was also evaluated with respect to simulated soil moisture at anthesis and at grain maturity. Results using this approach were highly correlated with soil moisture results obtained from simulations based on the measured CLL values. This research provides strong evidence that the effects of SSCs on wheat yields are accounted for by the effects of these constraints on wheat CLL values. The study also produced two satisfactory methods for simulating the effects of SSCs on CLL and on grain yield. While Cl and ESP proved to be effective indices of SSCs, EC was not effective due to the confounding effect of the presence of gypsum in some of these soils. This study provides the tools necessary for investigating the effects of SSCs on wheat crop yields and natural resource management (NRM) issues such as runoff, recharge, and nutrient loss through simulation studies. It also facilitates investigation of suggested agronomic adaptations to SSCs.

Chloride Transport and Corrosion near the Transition Zone between Substrate and Repair Concrete - Field Study / Chloridtransport und Korrosion in der Nähe einer Grenzfläche zwischen Untergrund und Reparaturbeton - Beobachtungen in der Praxis

One of the major degradation problems in concrete structures is chloride initiated reinforcement corrosion resulting in cracked, spalled and delaminated concrete. Thesedamages are repaired for large amounts of money and because of high repair costs it is important to perform durable repairs. This thesis work has included interviews, laboratory and field studies in the area of concrete repairs. The interviews were held mainly with bridge engineers at the Swedish Road Administration and Banverket (the Swedish Railway Administration). The questions asked tothese people were about their experience in the field of concrete repairs. The objective withthe interview study was to collect knowledge and experience about concrete repair at these two governmental authorities. The main objective of the laboratory study was to investigate chloride transport in the transition zone between a chloride contaminated substrate concrete and an initially chloride free repair concrete by establishing chloride profiles. The second objective was to detect any reinforcement corrosion in relation to the transition zone. The reinforced laboratory specimens with premixed chlorides (1 or 4 wt % per cement) in the substrate concrete have been exposed during 13 years either outdoors or in a climate chamber with relative humidity of 80 %. The main results show that reinforcement corrosion occurred in and near the transition zone in local active areas with passive areas between, macrocell corrosion, and that the chlorides are transported from the contaminated substrate concrete into the repair concrete. Three different repaired concrete structures, one road bridge, one pedestrian bridge and one parking structure, were investigated in the field study. All three structures are treated with deicing agents in the winter time. The objective with the field study was to investigate if the same phenomenon can be observed as in the laboratory study. The main conclusions, from the investigation on drilled cores from each structure, are that chlorides in contaminated substrate concrete can be transported into a repair concrete and reinforcement corrosion may occur in the transition zone between the two different materials. The results are in accordance with the results in the laboratory study. It was also seen that a repair concrete with relative low w/cratio may reduce the ingress of external chlorides. Finally, the results in this thesis indicate that there is a risk for reinforcement corrosion in the vicinity of the transition zone between repair concrete and a substrate concrete which must be considered in concrete repair work. For example the chloride content around a repair must not exceed a certain level when a repair is performed. The chloride transport into the repair concrete can be useful to transport chlorides and reduce the content of chlorides in the substrate concrete. The advantages with this are that the amount of removed contaminated substrate concrete can be minimized and the risk for corrosion in the substrate concrete is lower. If the repair concrete is reinforced with conventional black steel there may on the other hand be a risk for corrosion in the repair concrete instead if high levels of chlorides are transported. Also external exposure of chlorides must be considered for the risk of corrosion in the repair material. Further research is needed about when different corrosion mechanisms and chloride diffusion mechanisms occur in reinforced concrete repairs. The experience from the used analyzing methods in the laboratory investigations are possible to use in coming research projects in the field of concrete repair. The next step after this thesis work should be in order to increase the understanding of the repaired concrete system including the important compatibility issues, the author believes that the most fruitful way consists of further laboratory investigations, field studies and optimisation of the repair material.

Investigation into the impact of abstraction on epiphyte species at Denge in Dungeness Special Area of Conservation

Dungeness in Kent is the largest shingle system in the British Isles, and comprises five distinct beaches. Denge Beach is the largest of these beaches and contains a series of open water bodies, which support a diversity of fauna and flora. Gravel extraction and water abstraction for public supply has been present in the Denge area since the end of the 19th century. A deterioration of a number of patches of blackthorn ( Prunus spinosa ) scrub and important epiphyte species found on the blackthorns was observed during the early 1990s. This paper examines the nature of the shingle aquifer, water-level fluctuations, the influence of human activity, and their relationship with the deterioration of blackthorn and epiphyte communities. It is found that water levels have steadily risen since the early 1990s and the deterioration of blackthorn scrub was probably related to high chloride levels caused by ingress of seawater.

Exploration of a Submerged Sinkhole Ecosystem in Lake Huron

Dissolution of the Silurian-Devonian aquifer in the Lake Huron Basin has produced several karst formations in the bedrock (sinkholes), through which groundwater emerges onto the lake floor. During September 2003, we explored a recently discovered submerged sinkhole ecosystem (55 m × 40 m × ∼1 m) located at a depth of 93 m with a remotely operated vehicle (ROV) equipped with a conductivity-temperature-depth (CTD) system, an acoustic navigational system, a video camera, and a water sampling system. In addition to two morphotypes of benthic mats, a 1–2 m thick visibly cloudy near-bottom nepheloid-like layer (sinkhole plume) with a strong hydrogen sulfide odor prevailed just above the seepage area of clear water. Relative to lake water, water samples collected within the sinkhole plume were characterized by slightly higher (by 4°C) temperatures, very high levels of chloride (up to 175 mg l−1) and conductivity (1,700 μS cm−1), as well as extremely high concentrations of sulfate (1,400 mg l−1), phosphorus (3 mg l−1) and particulate organic matter (400 mg C l−1). Compared to background lake water, sinkhole plume water was characterized by approximately twofold lower C:N ratios and tenfold higher levels of dissolved organic carbon, bacterial biomass as well as heterotrophic bacterial production. Significant uptake of 14C-bicarbonate in dark incubations provided preliminary evidence for occurrence of chemosynthesis, possibly mediated by specialized Bacteria and Archea present in this submerged sinkhole ecosystem in the Laurentian Great Lakes.

Effect of Different Chloride Concentrations on Nutrient Release in Wetland Soils: A Phytometer Assessment in the Botshol Wetlands, The Netherlands

Turbid water, high phosphorus (P)-loading and disappearing Chara communities forced local water authorities to carry out restoration measures in the lakes and marshes of the Botshol The Netherlands. The reduction of the external-P input could be reached by chemical treatment of the brackish suppletion water and by separating the area from nearby agricultural areas. A side effect of these measures was an increase of chloride from 400 mg l−1 to 1000 mg l−1 in the surface water of Botshol. Internal biogeochemical processes were investigated with phytometers and direct measurements of soil nutrient availability in greenhouse experiments. The increased chloride levels were assumed to increase soil pore water P. The first experiment showed higher P in the peat-soils treated with the highest Cl-concentration and an increased leaching of PO4 from the lake-bottom peat-soils. No reaction of the phytometer Epilobium hirsutum was found. In the second experiment the 800 mg l−1 Cl-treatment resulted in significantly higher biomass of Carex acutiformis grown on treated bank soil. N-uptake by the phytometer Carex acutiformis was significantly higher. The available-P and total-P in the bank soil did not show a treatment effect. The two studies showed under similar ‘standardized’ conditions a treatment effect of chloride on the P-availability, resulting in higher PO4 leaching and increased plant nutrient concentrations and biomass. The field study showed higher available-P concentrations in the shore zone than in remote areas. The high chloride levels after restoration impact internal nutrient availability in the Botshol wetlands, on soil loaded with P in recent and historic times.

Endogenous γ-Aminobutyric Acid Can Excite Gonadotropin-Releasing Hormone Neurons

gamma-Aminobutyric acid (GABA) provides a major synaptic input to GnRH neurons. GnRH neurons maintain high intracellular chloride levels and respond to exogenous GABA with depolarization and action potential firing. We examined the role of synaptic GABA type A receptor (GABA(A)R) activation on the firing activity of GnRH neurons. Targeted extracellular recordings were used to detect firing activity of GnRH neurons in brain slices from adult female mice. Because the brain slice preparation preserves both glutamatergic and GABAergic neuronal networks, the effects of GABA(A)Rs on GnRH neurons were isolated by blocking ionotropic glutamatergic receptors (iGluR). With iGluR blocked, many GnRH neurons remained spontaneously active. Consistent with an excitatory role for GABA, subsequent blockade of GABA(A)Rs suppressed the firing rate in active cells from diestrous females by approximately 40% (P < 0.05; n = 10). GABA(A)R blockade did not affect inactive cells (n = 7), indicating that GABA(A)R-mediated inhibition was not responsible for the lack of firing. In prenatally androgenized females, GnRH neurons exhibit larger, more frequent GABAergic postsynaptic currents than control females. Most cells from prenatally androgenized animals fired spontaneously, and the firing rate was suppressed approximately 80% after GABA(A)R blockade (P < 0.01; n = 8). Blocking GABA(A)R without blocking iGluRs increased the firing rate in GnRH neurons from diestrous females (P < 0.05; n = 6), perhaps attributable to hyperexcitability within the slice network. Our results indicate that GABAergic inputs help generate a portion of action potentials in GnRH neurons; this fraction depends on the level of GABA transmission and postsynaptic responsiveness. The complexities of the GnRH neuron response to GABA make this a potentially critical integration point for central regulation of fertility.

Influence of different types of fertilisers on the major antioxidant components of tomatoes

The objective of this study was to investigate the effect of three different mineral nutrient solutions (nitrate: ammonium ratios of 4:1 or 1:4), chicken manure and grass-clover mulch on the major carpometric and antioxidant components of greenhouse grown tomatoes. The mean plant shoot biomass was significantly higher ( P < 0.05 ) for the plants grown with mineral nutrient solutions (mean plant fresh weight, 1.05 kg) compared with chicken manure and grass-clover mulch (0.80 kg). However, there was no significant difference in the yield, dry matter content, or soluble solids of tomatoes grown with different forms of fertilisers for the duration of the experiment. The titratable acidity of tomatoes grown with nitrate-dominant solution was significantly lower ( P < 0.05 ) than tomatoes grown with other treatments. The mean total phenolic and ascorbic acid content of tomatoes grown using chicken manure and grass-clover mulch was 17.6% and 29% higher, respectively, than the tomatoes grown with mineral nutrient solutions. The mean lycopene content was 40% lower in tomatoes grown with high chloride levels and grass-clover mulch (11.5 mg/100 g dry matter) compared with other treatments (19.2 mg/100 g dry matter). The mean antioxidant activity of the ammonium-treated plants was 14% lower compared with other treatments. These results show that the nutrient source plays a major role in determining the levels of titratable acidity and antioxidant components in tomato.

Tubular and glomerular function in children after renal transplantation

Glomerular and tubular function of transplanted kidneys were assessed in 46 children aged 15.7 +/- 4.6 yr, 4.2 +/- 2.8 yr after renal transplantation. There were 34 cadaveric, and 12 living-related donors. Twelve patients (26%) had acute episodes (acute tubular necrosis, rejection, or urinary tract infection) during follow-up. All patients were on triple immunosuppression. The mean serum creatinine was 1.5 +/- 0.6 mg/dL. Creatinine clearance (Ccreat) calculated from a 24-h urine collection was 48.0 +/- 19.7 mL/min/1.73 m(2), and that estimated from the Schwartz formula, 61.0 +/- 22.5 mL/min/1.73 m(2). A positive correlation was found between the calculated and estimated clearances. Mean urine concentrating ability was 487 +/- 184 mOsmol/kg, with a value lower than 400 mOsmol/kg in 35% of patients. There was a positive correlation between urine osmolality and estimated Ccreat. Metabolic acidosis (bicarbonate <22 mmol/L) was found in 41% of patients, with relatively alkaline urine and high chloride level. Fractional excretion (FE) of sodium was above 1% in 68% of patients (mean 1.66 +/- 1.06%), and FE(Mg) was above 3% (mean 10.9 +/- 5.2%) in 93% of patients. Tubular reabsorption of phosphate (TP)/glomerular filtration rate (GFR) was 3.2 +/- 0.8 mg/dL glomerular filtrate (GF). FE(K), FE(UA), and Ca/creatinine in urine were normal. There were no functional group differences between the cadaveric and living-related kidneys. Significant group differences were found in those with acute episodes and those with a normal course. Estimated Ccreat was 54 +/- 20 vs. 67 +/- 20 mL/min/1.73 m(2) in the acute episodes and the normal course groups, respectively. Also, the FE(NA), FE(UA), and FE(Mg) were higher in the acute episodes group -2.3 +/- 1.6, 10.6 +/- 4.4, and 14.8 +/- 6.5%, respectively, compared with the normal course group -1.4 +/- 0.6, 8.2 +/- 2.8, and 9.6 +/- 4.0%, respectively. There were no between-group differences in plasma bicarbonate, FE(K), TP/GFR, and urine osmolality. We believe that most, if not all tubular dysfunctions in the transplanted kidney are secondary to renal failure and interstitial damage from acute episodes and nephrotoxic drugs. These dysfunctions are similar to those in chronic renal failure, where interstitial fibrosis plays a role in kidney function deterioration.