Neonatal paracetamol poisoning.
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Acetaminophen↗
Biomedical subjects
A J Baker
Publications and source records attributed to A J Baker.
The effect of short stature, portal hypertension, and cholestasis on growth hormone resistance in children with liver disease.
Chronic liver disease is associated with GH resistance, which is characterized by high circulating GH and low insulin-like growth factor I (IGF-I) concentrations. Standard GH replacement has no effect on serum IGF-I in pediatric liver disease. The aims were to examine whether GH resistance can be overcome by supraphysiological GH and to determine whether GH resistance worsens with the progression of liver disease. Thirty children, divided into five groups whose liver disease was at clinically different stages, were studied. They were given 0.2 IU/kg x day GH for 4 days and then 0.4 IU/kg x day for the next 4 days. Serum IGF-I and binding proteins (IGFBPs) were measured by immunoassay. IGF-I was lower in all study groups than in normal controls. IGF-I, IGFBP-3, and acid-labile subunit rose in response to GH. The magnitude of the response reflected nutritional status and liver dysfunction; in particular, portal hypertension was associated with a poor IGF-I response. There was no change in IGFBP-2. GH resistance begins early in the natural history of childhood liver disease and develops with the progression of liver disease, particularly with portal hypertension. It may be partially overcome by supraphysiological GH administration, but the effect becomes smaller with worsening liver disease.
Body Height↗
Gender matching and outcome after pediatric liver transplantation.
BACKGROUND: Gender is not a selection criterion for orthotopic liver transplantation (OLT), and reports in adults have shown a less favorable outcome for male recipients of female organs; the only pediatric study did not support this finding. The aim of the present study was to assess the impact of donor and recipient gender on graft and patient survival rates after pediatric OLT. METHODS: We have reviewed retrospectively 137 children (male=63; median age: 3.4 years; range: 14 days to 15 years) undergoing primary OLT from January 1991 to June 1996. These children were divided into donor-recipient gender match (M; n=64) and nonmatch (NM; n=73) groups and then classified into female to female (FF; n=30), female to male (FM; n=29), male to female (MF; n=44), and male to male (MM; n=34) subgroups. RESULTS: The M group had better graft and patient survival rates at both 1- and 5-year follow-up compared with the NM group (P<0.01). Graft and patient survival rates were different among gender subgroups (P<0.04). Graft and patient survival rates in the FM group were poorer than in the MM subgroup at both 1 and 5 years (P<0.03, P<0.01). The FM group had a higher incidence of early complications than the MM (P<0.01) group, with 50% and 33% of graft losses, respectively, related to the complications. To minimize the influence of hormonal factors, we have analyzed separately the patients younger than 12 and 10 years who had similar findings. CONCLUSION: Graft and patient survival rates after pediatric OLT are worse in gender mismatch groups, particularly for male recipients of female organs. Early complications play a role in the decreased survival rates.
Adolescent↗
Anti-thymocyte globulin, cyclosporin A and granulocyte colony-stimulating factor for severe aplastic anaemia complicating paediatric liver transplantation.
UNLABELLED: We describe a sustained trilineage haematopoietic response to intensified immunosuppressive therapy with anti-thymocyte globulin, cyclosporin A and recombinant human granulocyte colony-stimulating factor in a 4-year-old girl, who developed severe aplastic anaemia after orthotopic liver transplantation for fulminant liver failure induced by non A-E hepatitis. The outcome was successful and allows the following. CONCLUSION: Intense immunosuppression in combination with haemopoetic growth factors and antimicrobial prophylaxis should be considered as first line therapy in severe aplastic anaemia after orthotopic liver trans-plantation.
Anemia, Aplastic↗
Effect of aortic cannula characteristics and blood velocity on transcranial doppler-detected microemboli during cardiopulmonary bypass.
OBJECTIVES: Cerebral microemboli are responsible to a large extent for the neuropsychiatric deficits after cardiac surgery. Differences in cannula size during cardiopulmonary bypass (CPB) will result in different velocities of blood exiting the aortic cannula. This study determined whether the number of transcranial Doppler (TCD)-detected emboli in the middle cerebral artery (MCA) during CPB correlated with blood speed or the direction of flow as determined by the shape of the aortic cannula. DESIGN: Patients were studied prospectively for evidence of TCD-detected emboli. If patients met the inclusion criteria, the choice of cannula was determined by surgical preference. SETTING: All studies were conducted at a single tertiary care academic cardiac surgery hospital by a single observer. PARTICIPANTS: Thirty-two patients undergoing first-time elective aortocoronary bypass surgery who were free of neurologic dysfunction or peripheral vascular disease and weighed 60 to 85 kg were studied. Patients who had other concurrent cardiac operations or who were in cardiogenic shock were excluded. INTERVENTIONS: Three aortic cannula types for elective aortocoronary bypass surgery were used: 24F curved (n = 19), 24F straight (n = 6), and 22F straight (n = 7), with internal diameters (IDs) of 7.2, 6.6, and 5.9 mm, respectively. TCD-detected emboli were identified in the MCA. MEASUREMENTS AND MAIN RESULTS: The rate of TCD-detected emboli (0.02 to 11.4 emboli per minute) was not related to the velocity of blood (46 to 77 cm/s) and was not affected by the choice of either a straight or curved aortic cannula. CONCLUSIONS: The choice of a straight or curved aortic cannula or of a 24F versus 22F cannula may not be important with respect to the number of cerebral microemboli.
Blood Flow Velocity↗
Serum leptin and insulin in paediatric end-stage liver disease and following successful orthotopic liver transplantation.
OBJECTIVE: Leptin, the product of the ob gene, is a postulated feedback regulator of adiposity with appetite suppressant and catabolic effects. Catabolic states are associated with decreased body fat mass as a result of both nutritional and metabolic perturbation. Low serum leptin has been described previously in a number of catabolic states. It has been unclear whether the observed changes in leptin are a cause or consequence of changes in adiposity. Paediatric end-stage liver disease (ESLD) is characterized by decreased body fat mass and poor linear growth. Successful treatment by orthotopic liver transplantation (OLT) is accompanied by increase in fat mass. We investigated the hypothesis that serum leptin would be low in paediatric ESLD and that increase in body fat mass post-OLT would result in increased serum leptin. DESIGN: Serum leptin and insulin were measured by radioimmunoassay in children with ESLD before and after successful OLT and in age-matched controls. PATIENTS: Twenty-four children with ESLD attending the outpatient department of King's College Hospital, London and 10 age-matched controls. MEASUREMENTS: Anthropometric measurements were performed according to standard techniques and standard deviation (SDS) derived from population standards. Serum leptin and insulin were measured by radioimmunoassay. RESULTS: Serum leptin pre-OLT, leptin (4.06 micrograms/l, [3.45, 5.68] median, with 25th and 75th interquartile ranges) was significantly lower than controls (6.62 micrograms/l, [4.33, 8.05], P = 0.02). Following OLT, serum leptin fell to levels which were significantly lower than pre-OLT values (3.32 micrograms/l, [2.30, 3.99], P = 0.01). There was no significant difference between boys and girls either pre-OLT (boys; 3.64 micrograms/l, [2.45, 5.57], girls; 4.14 micrograms/l, [3.18, 5.65]) or post-OLT (boys; 3.32 micrograms/l, [2.93, 3.62], girls; 3.69 micrograms/l, [2.23, 4.63]. Neither the age at OLT nor the age at the time of blood sampling was correlated with serum leptin pre-OLT or post-OLT. Pre-OLT the children were significantly malnourished with low measures of body fat mass (mid-arm circumference (MAC) SDS -1.90 [-4.67, -1.07]; triceps skinfold thickness (TSF) SDS -1.53, [-2.23, -0.23]; body mass index (BMI) 16.2, [15.5, 16.9]). Three months post-OLT, there were significant improvements in MAC SDS (-0.77, [-1.08, -0.20], P = 0.02) and TSF SDS (-0.41, [-1.95, -0.38], P = 0.003), but no significant change in BMI (15.9 [15.3, 16.7], P = 0.41. Pre-OLT, log serum leptin did not correlate with BMI, MAC SDS or TSF SDS. In contrast, post-OLT, there was a positive correlation between log serum leptin and BMI (r = 0.59, P = 0.003), MAC SDS (r = 0.49, P = 0.01) and TSF SDS (r = 0.41, P = 0.05). BMI also correlated with log serum leptin in the control children (r = 0.64, P = 0.04). CONCLUSIONS: Serum leptin is low in children with end-stage liver disease but does not show the expected correlation with measures of body fat mass. Surprisingly, following orthotopic liver transplantation serum leptin falls significantly despite significant increases in measures of body fat mass (triceps skinfold thickness standard deviation scores, mid-arm circumference standard deviation scores). Orthotopic liver transplantation restores the expected correlation of serum leptin with measures of body fat mass within the treatment group. The elevation of serum leptin above predicted levels in paediatric end-stage liver disease offers a mechanism for the anorexia and cachexia characteristic of this disease.
Anthropometry↗
An assessment of the radiation dose to patients and staff from a Lunar Expert-XL fan beam densitometer.
Dual-energy x-ray absorptiometry (DXA) is a widely used technique for measuring bone mineral density for the identification and management of osteoporotic subjects. The original DXA pencil beam systems expose patients to an effective dose of ionizing radiation of around 2 muSv and require no additional protective shielding for staff. The new fan beam densitometers incorporate solid state detectors and have a higher photon flux, enabling faster acquisition times and giving improved resolution. However, this may be at the expense of higher radiation dose. This study was conducted to assess the radiation dose to patients and staff from the standard scan modes using a Lunar Expert-XL fan beam densitometer. This is, we believe, the first dose assessment of the Expert-XL. The results indicate that the scatter dose at 1 m from the scan table, assuming four AP spine and femoral neck examinations per hour, is about 4 muSv h-1. This is well below the limit of 7.5 muSv h-1 set by the UK's Ionising Radiation Regulations for defining a Controlled Area but above the lesser limit of 2.5 muSv h-1 for a Supervised Area. Typical effective doses to patients are 59 muSv for an AP lumbar spine scan, up to 56 muSv for AP femoral neck, 71 muSv for lateral spine morphometry and 75 muSv for whole body. Although exceeding those of pencil beam DXA machines, these doses are less than for standard radiographic procedures, particularly of the lumbar spine. Where reduced scan time, improved image resolution or morphometric analysis of the spine are required, the patient doses from the Lunar Expert-XL are not prohibitive.
Absorptiometry, Photon↗
Clinical significance of CSF glutamate concentrations following severe traumatic brain injury in humans.
Glutamate excitotoxicity is a putative mechanism of secondary damage after traumatic brain injury (TBI). No relationship between glutamate release and clinical status has been shown in humans, however. We hypothesize a dose-response relationship between CSF glutamate concentrations and severity of injury, electrophysiological deterioration as measured by somatosensory evoked potential amplitudes, and clinical outcome. From August 1991 to March 1996, intensive monitoring of 55 patients with severe TBI (GCS < or = 8 after resuscitation) included twice daily CSF glutamate levels and hourly somatosensory evoked potentials (SSEPs) for an average of 5 days. Clinical outcomes were survival/nonsurvival and Glasgow outcome score (GOS) at 3 months or more post-injury. Glutamate levels were not associated with severity of injury, electrophysiological deterioration, or clinical outcome. Neither peak nor mean glutamate levels significantly improved a simple logistic regression model which used only age and presence of bilaterally unreactive pupils to predict survival. Using this methodology CSF glutamate concentrations did not display a dose-response relationship to severity of injury, electrophysiological deterioration, or predict clinical outcomes following TBI in a group of 55 patients. An early effect of glutamate, an effect dependent on time of exposure to glutamate or other modulating effects cannot be ruled out.
Adult↗
Rates and patterns of mitochondrial DNA sequence evolution in fringilline finches (fringilla spp.) and the greenfinch (Carduelis chloris).
Rates and patterns of evolution in partial sequences of five mitochondrial genes (cytochrome b, ATPase 6, NADH dehydrogenase subunit 5, tRNA(Glu), and the control region) were compared among taxa in the passerine bird genera Fringilla and Carduelis. Rates of divergence do not vary significantly among genes, even in comparisons with the control region. Rate variation among lineages is significant only for the control region and NADH dehydrogenase subunit 5, and patterns of variation are consistent with the expectations of neutral theory. Base composition is biased in all genes but is stationary among lineages, and there is evidence for directional mutation pressure only in the control region. Despite these similarities, patterns of substitution differ among genes, consistent with alternative regimes of selective constraint. Rates of nonsynonymous substitution are higher in NADH dehydrogenase subunit 5 than in other protein-coding genes, and transitions exist in elevated proportions relative to transversions. Transitions appear to accumulate linearly with time in tRNA(Glu), and despite exhibiting the highest overall rate of divergence among species, there are no transversional changes in this gene. Finally, for resolving phylogenetic relationships among Fringilla taxa, the combined protein-coding data are broadly similar to those of the control region in terms of phylogenetic informativeness and statistical support.
Animals↗
Cerebral oxidative metabolism and evoked potential deterioration after severe brain injury: new evidence of early posttraumatic ischemia.
BACKGROUND: We commonly observe progressive deterioration in somatosensory evoked potentials (SSEPs) after severe head injury. We had previously been unable to relate this deterioration to raised intracranial pressure but had noted a relationship with decreasing transcranial oxygen extraction (arteriovenous oxygen difference [AVDO2]). The purpose of this study was twofold: to prove the hypothesis that deterioration in SSEP values is associated with decreasing AVDO2 and to test the subsidiary hypotheses that deteriorating SSEPs were the result of either ischemia/reperfusion injury or failure of oxygen extraction/utilization. METHODS: Monitoring of 97 patients with severe traumatic brain injury (Glasgow Coma Scale scores of < or = 8 after resuscitation) included twice daily AVDO2 measurement and hourly SSEP recording for an average of 5 days. The last 51 patients also underwent 12-hourly measurement of cerebral blood flow (CBF), with calculation of the cerebral metabolic rate of oxygen. Cluster analysis was used to classify patients based on initial AVDO2 values and subsequent SSEP trends. The time courses of CBF, SSEPs, AVDO2, and cerebral metabolic rate of oxygen were examined in the groups defined by the cluster analysis. The clinical outcomes considered were survival or nonsurvival and the Glasgow Outcome Scale scores obtained at 3 months or more after injury. RESULTS: Cluster analysis confirmed the association between high initial AVDO2 values and subsequent SSEP deterioration. Patients in this category initially had significantly higher AVDO2, lower CBF, and higher cerebral metabolic rates of oxygen but recovered to adequate levels within 24 to 36 hours after injury. SSEP values were initially identical in the patients with normal AVDO2 values and those with elevated AVDO2 but differed significantly at 60 hours after injury and beyond. CONCLUSION: The findings of increased oxygen utilization and lowered CBF in the patients with deteriorating SSEPs strongly imply that early ischemia rather than failure of O2 extraction or utilization is responsible for the associated SSEP deterioration. This issue of defining thresholds for ischemia based on AVDO2 is confounded by the dependency of CBF and AVDO2 values on the time after injury.
Adult↗
Chronic alcohol-induced changes in cardiac contractility are not due to changes in the cytosolic Ca2+ transient.
Long-standing heavy alcohol consumption acts as a chronic stress on the heart. It is thought that alcohol-induced changes of contractility are due to altered Ca2+ handling, but no measurements of cytosolic Ca2+ ([Ca2+]c) after chronic alcohol exposure have been made. Therefore experiments were performed to determine whether alcohol-induced changes in contractility are due to altered Ca2+ handling by measuring [Ca2+]c (indo 1) in hearts from rats drinking 36% ethanol for 7 mo and age-matched controls. Peak left ventricular pressure was depressed (-16%), whereas rates of contraction (12%) and relaxation (14-20%) were faster in alcohol-exposed hearts. Systolic [Ca2+]c (808 +/- 45 vs. 813 +/- 45 nM), diastolic [Ca2+]c (195 +/- 11 vs. 193 +/- 10 nM), and rates of [Ca2+]c rise and decline were the same in alcohol-exposed and control hearts. Protein levels of Ca2+-handling proteins, sarcoplasmic reticulum Ca2+-ATPase and phospholamban, were the same in myocytes isolated from alcohol-exposed and control hearts (SDS-polyacrylamide gel). These data suggest that chronic alcohol-induced contractile changes are not due to altered Ca2+ handling but may be due to changes at the level of the myofilament. As a first step in elucidating the mechanism(s) of alcohol-induced changes at the myofilament, we assessed myosin heavy chain (MHC) isoform content (SDS-polyacrylamide gel). alpha-MHC was decreased relative to beta-MHC (a/a + b = 0.55 +/- 0.03 vs. 0.66 +/- 0.02; P < 0.02) in alcohol-exposed hearts, which cannot account for the observed alcohol-induced contractile changes. In conclusion, changes of myocardial contractility due to chronic alcohol exposure do not result from altered Ca2+ handling but from changes at the level of the myofilament that do not involve MHC isoform shifts.
Alcohol Drinking↗
Ca2+ regulates the kinetics of tension development in intact cardiac muscle.
The goal of this study was to determine whether Ca2+ plays a role in regulating tension development kinetics in intact cardiac muscle. In cardiac muscle, this fundamental issue of Ca2+ regulation has been controversial. The approach was to induce steady-state tetanic contractions of intact right ventricular trabeculae from rat hearts at varying external Ca2+ concentrations ([Ca2+]) at 22 degreesC. During tetani, cross bridges were mechanically disrupted and the kinetics of tension redevelopment were assessed from the rate constant of exponential tension redevelopment (ktr). There was a relationship between ktr and external [Ca2+] that was similar in form to the relationship between tension and [Ca2+]. Thus a close relationship also existed between ktr and tension (r = 0.88; P < 0. 001); whereas at maximal tetanic tension (saturating cytosolic [Ca2+]), ktr was 16.4 +/- 2.2 s-1 (mean +/- SE, n = 7), at zero tension (low cytosolic [Ca2+]), ktr extrapolated to 20% of maximum (3.3 +/- 0.7 s-1). Qualitatively similar results were obtained using different mechanical protocols to disrupt cross bridges. These data demonstrate that tension redevelopment kinetics in intact cardiac muscle are influenced by the level of Ca2+ activation. These findings contrast with the findings of one previous study of intact cardiac muscle. Activation dependence of tension development kinetics may play an important role in determining the rate and extent of myocardial tension rise during the cardiac cycle in vivo.
Animals↗
The insulin-like growth factor and binding protein axis in children with end-stage liver disease before and after orthotopic liver transplantation.
Over 50% of children with established cirrhosis have evidence of growth failure and malnutrition. Orthotopic liver transplantation (OLT) is a successful treatment for many children and leads to improved growth and nutrition. Most of the anabolic actions of GH are mediated through the generation of the mitogenic polypeptide insulin-like growth factor-I (IGF-I). Although this is synthesised ubiquitously, the bulk of circulating IGF-I is derived from the liver. The actions of IGF-I are modulated by a family of at least six high-affinity binding proteins (IGFBPs). Growth failure in end-stage liver disease, both before and after OLT, may result from abnormalities in the IGF-IGFBP axis. Children who had undergone successful OLT were studied before and after OLT. Anthropometry was measured by standard techniques. Serum IGFs, IGFBPs and acid labile subunit (ALS) were measured by RIA, IRMA, ELISA, Western ligand and immunoblotting. The most severely affected anthropometric parameters were skin fold thickness and mid-arm circumference. After OLT there was a marked improvement in these parameters. Chronic liver disease was characterised by low serum IGF-I, IGF-II, IGFBP-3 and ALS levels with raised IGFBP-1 and -2 levels. Serum IGFBP-1 and -2 were negatively correlated with pre-OLT anthropometric parameters. After OLT, there was a rapid normalisation of serum IGF-I, while IGF-II and IGFBP-3 overshot to supranormal levels. ALS levels post-OLT remained below control levels. By 3 years post-OLT, IGFBP-3 had fallen to levels which were insignificantly different from controls. IGFBP-1 fell but remained above normal, while there was no significant change in IGFBP-2. Growth post-OLT correlated positively with serum IGF-I and negatively with IGFBP-1. In conclusion, chronic liver disease is associated with marked changes in body composition. These changes are associated with and may be caused by an impaired generation of IGF-I and altered production of IGFBPs. After OLT there is a marked improvement in growth associated with partial normalisation of the IGF-IGFBP axis. However, there are persistent abnormalities in this axis which may explain growth failure post-OLT.
Adolescent↗
Enigmatic phylogeny of skuas (Aves:Stercorariidae)
Multiple sources of evidence show that the skuas (Aves:Stercorariidae) are a monophyletic group, closely related to gulls (Laridae. On morphological and behavioural evidence the Stercorariidae are divided into two widely divergent genera, Catharacta and Stercorarius, consistent with observed levels of nuclear and mitochondrial gene divergence. Catharacta skuas are large-bodied and with one exception breed in the Southern Hemisphere. Stercorarius skuas otherwise known as jaegers) are smaller bodied and breed exclusively in the Northern Hemisphere. Evidence from both mitochondrial and nuclear genomes and from ectoparasitic lice (Insecta:Phthiraptera) shows that the Pomarine skua, S. pomarinus, which has been recognized as being somewhat intermediate in certain morphological and behavioural characteristics, is much more closely related to species in the genus Catharacta, especially to the Northern Hemisphere-breeding Great skua, C. skua, than it is to the other two Stercorarius skuas, the Arctic skua, S. parasiticus and the Longtailed skua, S. longicaudus. Three possible explanations that might account for this discordant aspect of skua phylogeny are explored. These involve (i) the segregation of ancestral polymorphism, (ii) convergent evolution of morphology and behaviour or (iii) inter-generic hybridization. The available evidence from both nuclear and mitochondrial genomes does not exclude any of these hypotheses. Thus, resolution of this enigma of skua phylogeny awaits further work.
Animals↗
Hepatic growth hormone receptor, insulin-like growth factor I, and insulin-like growth factor-binding protein messenger RNA expression in pediatric liver disease.
Major changes in serum levels of insulin-like growth factor I (IGF-I) and IGF-binding proteins (IGFBPs) occur in children with end-stage liver disease in association with changes in body composition. We hypothesized that these changes would be associated with changes in hepatic messenger RNA (mRNA) expression. Eleven children with end-stage extrahepatic biliary atresia and 11 controls (liver donors) were studied. Serum samples were obtained from the children with biliary atresia immediately before orthotopic liver transplantation. Serum IGF-I, IGFBP-1, and IGFBP-2 levels were measured by radioimmunoassay, and IGFBP-3 by immunoradiometric assay. In both groups, growth hormone receptor mRNA expression was examined by quantitative reverse transcription-polymerase chain reaction, IGF-I mRNA expression by ribonuclease protection assay, and IGFBP-1 to -4 mRNA expression by Northern analysis. Growth hormone receptor and IGF-I mRNA levels were reduced 1.7-fold (P = .003) and 9.6-fold (P = .0001) in biliary atresia compared with levels in controls. Despite increased serum IGFBP-1 levels and reduced IGFBP-3 levels in biliary atresia, there was no change in either IGFBP-1 or IGFBP-3 mRNA expression. In contrast, serum levels and mRNA expression of IGFBP-2 were increased 1.6-fold (P = .003) and twofold (P = .0001), respectively, compared with controls. Gene expression did not correlate with liver dysfunction or body composition. Changes in growth hormone receptor and IGF-I mRNA expression may account for the reduction in serum IGF-I found in pediatric liver disease. In contrast, the marked alteration in circulating IGFBP levels was not accompanied by changes in hepatic IGFBP gene expression, suggesting that posttranslational mechanisms may be important.
Adolescent↗
Ocular ultrasound in Alagille syndrome: a new sign.
BACKGROUND: Alagille syndrome (AS) is one of six forms of familial intrahepatic cholestasis, all of which present with neonatal jaundice and paucity of intrahepatic bile ducts. Differentiation of these individual syndromes is crucial as their treatments and prognoses vary. It is the ophthalmic features, posterior embryotoxon on particular, that distinguish AS. METHODS: The authors performed full ocular examination, including A- and B-scan ultrasound, refraction, and, where possible, fluorescein angiography in 20 unrelated children with AS and 8 with non-AS-related cholestasis. RESULTS: There was ultrasound evidence of optic disc drusen in at least one eye in 95% and bilateral disc drusen in 80% of patients with AS but in none of the patients who were non-AS at the time of examination. Independent review of hard-copy scans suggested drusen in at least one eye in 90% of the cases and bilateral drusen in 50%, although this latter figure rose to 65% on review of the angiograms. This is markedly higher than the incidence in the normal population (0.3%-2%). Axial lengths were shorter than expected for the older age group (older than 10 years of age), but this was not associated with gross ametropia. CONCLUSION: This strong association of AS and optic disc drusen has not been reported previously and represents not only the first significant association between a systemic condition and disc drusen but also a possibly useful tool in the diagnosis of AS, especially in young children.
Adolescent↗
The pathogenesis of growth failure in paediatric liver disease.
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Animals↗
Phytoremediation of soil metals.
The phytoremediation of metal-contaminated soils offers a low-cost method for soil remediation and some extracted metals may be recycled for value. Both the phytoextraction of metals and the phytovolatilization of Se or Hg by plants offer great promise for commercial development. Natural metal hyperaccumulator phenotype is much more important than high-yield ability when using plants to remove metals from contaminated soils. The hypertolerance of metals is the key plant characteristic required for hyperaccumulation; vacuolar compartmentalization appears to be the source of hypertolerance of natural hyperaccumulator plants. Alternatively, soil Pb and Cr6+ may be inactivated in the soil by plants and soil amendments (phytostabilization). Little molecular understanding of plant activities critical to phytoremediation has been achieved, but recent progress in characterizing Fe, Cd and Zn uptake by Arabidopsis and yeast mutants indicates strategies for developing transgenic improved phytoremediation cultivars for commercial use.
Biological Transport, Active↗