Usefulness of lead isotopes analysis in a pediatric case of chronic lead poisoning

Identifying the source of lead is a key measure in the management of childhood lead poisoning. In cases with multiple potential sources or with unusual circumstances, this identification can be complex. By comparing the lead isotopic ratios (IRs) between the potential sources and the blood sample from the patient, it is possible to identify which source caused the poisoning. We report here the case of a 13-years-old girl, screened for lead poisoning as she was known to eat paint chips from two walls in her apartment. Her blood lead level was 395 µg/L, and the environmental investigation came back negative. X-ray fluorescence found lead concentration in paints to be below the regulatory threshold of 1 mg/cm². As there was no other potential source of lead exposure in this case, a comparative analysis of the IRs of lead between the child's blood and two presumed sources (bathroom and kitchen paints) was performed. This analysis confirmed the source of lead intoxication to be the paints in the apartment, mostly from the bathroom wall.

Exchangeable copper: a reflection of the neurological severity in Wilson's disease

BACKGROUND AND PURPOSE

The severity of Wilson's disease (WD) is linked to free copper accumulating in the liver and brain. Exchangeable copper (CuEXC) is a new technique to determine plasmatic copper and is useful in the diagnosis of WD. It is hypothesized that it may also enable a good evaluation of extra-hepatic involvement and its severity.

METHODS

Forty-eight newly diagnosed WD patients were prospectively evaluated using hepatic, neurological, ophthalmological and brain magnetic resonance imaging (MRI) scores. Three phenotypic presentations were distinguished: pre-symptomatic, hepatic and extra-hepatic. CuEXC was determined in addition to standard copper assays before decoppering therapy. Correlations between biological parameters and the different scores were determined and compared in the hepatic and extra-hepatic groups.

RESULTS

Extra-hepatic patients had significantly higher CuEXC values than those with the hepatic form (P < 0.0001). The overall ability of CuEXC to separate the two forms was satisfactory, with an area under the curve of 0.883 (95% confidence interval 0.771-0.996) and an optimal threshold for extra-hepatic diagnosis of 2.08 μmol/l (sensitivity 85.7%; specificity 94.1%). In extra-hepatic patients, CuEXC was the only biological marker to be positively correlated with the Unified Wilson Disease Rating Score (r = 0.45, P = 0.016), the Kayser-Fleischer ring score (r = 0.46, P = 0.014) and the brain MRI score (r = 0.38, P = 0.048), but it was not correlated with the hepatic score.

CONCLUSIONS

Exchangeable copper determination is useful when diagnosing WD as a value >2.08 μmol/l is indicative of the severity of the extra-hepatic involvement. In the case of purely hepatic presentation, atypical or mild neurological signs, it should encourage physicians to search for lesions in the brain and eyes.

The embalming of John of Lancaster, first Duke of Bedford (1435 AD): A forensic analysis

During the Middle Ages and Renaissance, embalming the cadaver of the elite was common practice, being a highly technical treatment mixing vegetal and mineral substances. To assess the exact kind of embalming reserved for the dead body (with the practical necessities of desiccation and good odour), we performed a full biomedical analysis of the mummified remains of John Plantagenet of Lancaster, first Duke of Bedford, regent of France for his nephew, the English King Henri VI (died 1435 AD). Here, we show, among other aspects, that the body was embalmed using substances whose origins were in apothecary and botany: mercury, myrtle, mint, frankincense, lime and, possibly, cinnamon and copper.

Corpus callosum abnormalities in Wilson's disease

INTRODUCTION

Wilson's disease (WD) with neurological presentation is associated with brain lesions classically localised in globus pallidus, putamen, thalamus, mesencephalon, pons and dentate nucleus. Lesions of corpus callosum (CC) have not been studied in a broad population of patients with WD.

OBJECTIVE

Evaluation of the frequency of CC lesions in patients with neurological symptoms related to WD.

METHOD

The authors included all patients with neurological expression of WD, followed in the French national centre for WD who had a brain MRI between March 2006 and December 2008. The localisation of brain lesions was analysed and the frequency of lesions in CC evaluated. All patients were assessed using the Unified Wilson's Disease Rating Scale. For patients with abnormalities located in CC, a clinical dysconnexion syndrome was investigated.

RESULTS

Among 81 patients (45 men, mean age: 34.8 years, from 12 to 74 years) with neurological expression, 42% had white-matter lesions on fluid-attenuated inversion recovery MRI. 23.4% of patients presented CC lesions, limited to the posterior part (splenium). The severity of disability estimated by Unified Wilson's Disease Rating Scale was correlated with the presence of CC lesions on MRI.

CONCLUSION

Abnormalities in CC are not unusual (23.4%). Together with lesions of basal ganglia, CC signal changes should suggest the diagnosis of WD.

Identifying sources of lead exposure for children, with lead concentrations and isotope ratios

Despite a dramatic decrease in children's blood lead levels (BLL), lead exposure remains a public health concern because increasing evidence shows effects at very low doses. Lowering BLL still further requires the identification of lead sources and, therefore, new tools to investigate and thus prevent exposure. We describe a procedure that uses both lead concentrations and isotope ratios (IRs) to identify sources of overexposure in homes. Water, dust, and paint chips were sampled from the homes of 21 children with elevated BLL from Aubervilliers (Paris metropolitan area). Lead concentrations of concern were calculated from reverse physiologically based pharmacokinetic modeling for water and dust. Isotope ratio matching of blood and environmental samples (with a lead content above the concentration of concern) was performed by computation of the distance between their IRs. When the IR of the source did not match that of the blood, the source was eliminated as a source of lead intoxication. The number of sources eliminated (per child) due to lead concentration ranged from 14% to 86% (mean 66%) for dust, and 100% for water samples. The number of remaining potential sources eliminated by IR interpretation varied from 0% to 100% for both dust and paint chips (mean 63% and 58%, respectively). IRs made it possible to eliminate at least one source in 20 of 21 cases and identified a single source in 11 of 21. The number of dust and paint sources not eliminated by concentration or IR varied from 8% to 45% (median 18%). The pilot study supports the usefulness of these procedures and the added value of IRs for identifying sources of lead poisoning. However, systematic use should be supported by cost-effectiveness analysis on a larger and more representative population of elevated BLL.

[Serum selenium and dilated cardiomyopathy in Cotonou, Benin]

PURPOSE

Peripartum cardiac failure is common in savannah-Sahelian Africa. It is due to a form of dilated cardiomyopathy (DCM) known as peripartum cardiomyopathy (PPCM) that results from undetermined causes. Numerous risk factors have been identified and dietary selenium deficiency has been proposed as a possibility. The purpose of this study was to measure serum selenium levels in patients presenting cardiac insufficiency due to PPCM and DCM (nonpostpartum) in Cotonou, Benin and to compare patients with healthy postpartum women with comparable or identical obstetric features.

METHODS

Measurements of selenium status were performed in 10 women (mean age, 27.1 years) with PPCM, 18 patients of both sexes (male/female, 11/7; mean age, 38.9 years) with DCM (non-peripartum), and 46 healthy recent post partum women (mean age, 29.8 years). The Wilcoxon nonparametric test was used for data analysis with a statistical significance level at a p-value <0.05.

RESULTS

Mean serum selenium values were near similar in patients presenting PPCM and DCM (non peripartum): 94 +/- 12 microg/L versus 97 +/- 19 microg/L respectively. This difference was not significant. No value was less than 72 microg/L. Conversely significantly lower mean values were observed in the 46 healthy recent postpartum women: 76 +/- 13 microg/L (p = 0.0002). The lowest value was 57 microg/L.

CONCLUSION

Serum selenium measurements in Cotonou showed that levels were higher in patients presenting PPCM or DCM (nonperipartum) than in healthy controls. Extremely low values were never observed. These results differed from those obtained in Bamako, Mali and in Niamey, Niger and argue against considering selenium deficiency as a risk factor for development of DCM (peripartum or not) in Cotonou.

[Pineapple juice as a negative oral contrast agent in magnetic resonance cholangiopancreatography]

PURPOSE

The quality of magnetic resonance cholangiopancreatography (MRCP) images is frequently degraded by high signal from the gastrointestinal tract on heavily T2W images. The purpose of this study is to evaluate pineapple juice (PJ) as an oral negative contrast agent in MRCP.

MATERIALS AND METHODS

Results from MRCP in 50 patients with PJ and 50 patients with paramagnetic contrast (ferumoxsil-Lumirem) were compared. Reviewers were blinded to the type of contrast agent. Exam quality was recorded with regards to signal suppression in the stomach, duodenum and proximal small bowel and with regards to pancreatic duct and biliary ducts visualization. In vitro, the signal characteristics of several commercially available brands of PJ were assessed using T1W, T2W and MRCP sequences. Signal intensity was correlated with the manganese concentration measured using atomic absorption spectrometry. Finally, the reviewers compared the taste of PJ and ferumoxsil.

RESULTS

On MRCP sequences, results were similar with regards to signal suppression in the stomach, duodenum and proximal small bowel with PJ and ferumoxsil. Visualization of the pancreatic duct, intrahgepatic bile ducts and CBD was similar with PJ and ferumoxsil. The signal intensity of commercially available brands of PJ on T2W and MRCP sequences correlated well with the measured manganese concentration on spectroscopy. Variations in manganese concentration were observed, with values ranging from 3.65 to 27.24 mg/L. The reviewers noted that PJ tasted "good" or "very good" and that ferumoxsil tasted "bad" or "very bad".

CONCLUSION

Ingestion of PJ provides effective signal suppression in the GI tract on MRCP, similar to paramagnetic contrast agents. Because manganese concentration is highly variable in commercially available PJ brands, a brand with high manganese concentration should be selected.

Ethanol oxidation into acetaldehyde by 16 recombinant human cytochrome P450 isoforms: Role of CYP2C isoforms in human liver microsomes

The involvement of cytochromes P450 (CYPs) in the oxidation of ethanol into acetaldehyde was investigated by using 16 recombinant human CYP isoforms. Apparent K(m) and V(m) were determined for CYP1A1, CYP1A2, CYP1B1, CYP2A6, CYP2B6, CYP2C8, CYP2C9*1, CYP2C9*2, CYP2C9*3, CYP2C18, CYP2C19, CYP2D6, CYP2E1, CYP2J2, CYP3A4 and CYP4A11. All of the tested CYPs, except CYP2A6 and CYP2C18, metabolized ethanol into significant amounts of acetaldehyde and displayed K(m) values around 10mM. The significant correlation found between ethanol oxidation and CYP2E1, CYP3A4 and CYP1A2 catalytic activities in a panel of human liver microsomes confirmed the strong implication of these CYPs in ethanol metabolism. The contribution of CYP2C isoforms which are the most abundant in the liver after CYP3A4, was studied using selective inhibitors either with recombinant CYP2C isoforms or in human liver microsomes. Tienilic acid (100 microM) and ticlopidine (20 microM), mechanism-based inhibitors of CYP2C9 and CYP2C19, respectively, decreased ethanol oxidation by 8+/-1.2% and 7.6+/-1.6% in human liver microsomal samples while selective inhibitors of CYP2E1 (DEDTC 100 microM), CYP3A4 (TAO 50 microM) and CYP1A2 (furafylline 25 microM) decreased it by 11.9+/-2.1%, 19.8+/-1.9% and 16.3+/-3.9%, respectively. As ethanol can be metabolized by most of CYPs, it helps to explain or predict alcohol-xenobiotics interactions which are of high importance in medical prescription.

Evaluation of tumoral enhancement by superparamagnetic iron oxide particles: comparative studies with ferumoxtran and anionic iron oxide nanoparticles

This study was designed to compare tumor enhancement by superparamagnetic iron oxide particles, using anionic iron oxide nanoparticles (AP) and ferumoxtran. In vitro, relaxometry and media with increasing complexity were used to assess the changes in r2 relaxivity due to cellular internalization. In vivo, 26 mice with subcutaneously implanted tumors were imaged for 24 h after injection of particles to describe kinetics of enhancement using T1 spin echo, T2 spin echo, and T2 fast spin echo sequences. In vitro, the r2 relaxivity decreased over time (0-4 h) when AP were uptaken by cells. The loss of r2 relaxivity was less pronounced with long (Hahn Echo) than short (Carr-Purcell-Meiboom-Gill) echo time sequences. In vivo, our results with ferumoxtran showed an early T2 peak (1 h), suggesting intravascular particles and a second peak in T1 (12 h), suggesting intrainterstitial accumulation of particles. With AP, the late peak (24 h) suggested an intracellular accumulation of particles. In vitro, anionic iron oxide nanoparticles are suitable for cellular labeling due to a high cellular uptake. Conversely, in vivo, ferumoxtran is suitable for passive targeting of tumors due to a favorable biodistribution.

A clinical and pharmacological study of arsenic trioxide in advanced multiple myeloma patients

We previously showed that arsenic trioxide (ATO) and melarsoprol may inhibit the growth of multiple myeloma (MM) cells in vitro and in vivo. We report here the administration of arsenic derivatives in 12 relapsing or refractory secretory MM patients. A total of 10 patients received ATO (eight in a continuous schedule, two discontinuously) and two received melarsoprol. The melarsoprol arm was prematurely closed due to toxicity. In the ATO arm, median duration of treatment was 38 days (9-54). Hepatic toxicity was grade 3 and 2 in one and eight patients, respectively. Other toxicities included neuropathy (n=2, grade 2), encephalitis (n=1, grade 3) and leuconeutropenia (n=4, grade 3). At 2 weeks after treatment initiation, mean serum concentration of arsenic was 1.11+/-0.16 micromol/l. No complete or partial remission was observed. A minor response (25-49% reduction of M protein in serum) and a stabilization of the M-protein level were observed in three and four patients, respectively. After ATO discontinuation, these responses were of short duration in all cases. ATO as a single agent did not produce any significant response in advanced MM patients despite sufficient arsenic exposure. Strategies to improve biodistribution, pharmacokinetic and efficacy of the drug as well as treatment combinations are needed.

Lead accumulation in the mouse ovary after treatment-induced follicular atresia

Although the main target of lead (Pb) toxicity is the red blood cell, Pb-associated changes in the nervous system, the kidney, and the reproductive system have also been described. The few Pb studies conducted on females revealed mostly miscarriages, premature delivery, and infant mortality in humans and animals. This study was done to correlate Pb accumulation in the ovary with damage to folliculogenesis. Pb burden was assayed by atomic absorption spectrometry in bone, liver, adrenal glands, ovary, and fetuses taken from mice exposed according to 2 protocols: intraperitoneal (i.p.) injection of Pb(NO(3))(2) 10 mg/kg/day for 15 days or 10 mg/kg/week for 15 weeks. Ovaries were examined histologically. Pb accumulation in the various soft tissues of acutely exposed mice was similar, and significantly higher than in the organs of chronically exposed mice. A low Pb concentration in the ovary caused dysfunction of folliculogenesis, with fewer primordial follicles and an increase in atretic antral follicles.

Dynamic study about metal release from titanium miniplates in maxillofacial surgery

It has been shown that titanium (Ti) has had dramatic success in many surgical procedures as a result of its excellent mechanical properties and resistance to corrosion. There is still concern, however, about the release of metal and controversy surrounding whether or not the plates should be removed after bone healing. This study has been conducted to investigate whether or not there is a relationship between duration of plating and metal release from Ti miniplates in maxillofacial surgery. A prospective cohort study design was used. The concentration of Ti, in the soft tissues covering the plates, was examined in all patients who underwent removal of Ti miniplates from January 1998 to April 1999 (51 cases). Inductively Coupled Plasma-Optical Emission Spectrometry was used to measure Ti. Total ti and soluble Ti levels were compared to duration of plating (ranged from 15 days to 3 years, mean = 8 months). Correlation coefficients and two-way ANOVA were data processed. The average amount of total Ti in the soft tissues surrounding the plates was 1306 micrograms/g dry tissue. The mean of soluble Ti was 0.53 microgram/g dry tissue. The results of this study do not support the existence of a relationship between duration of plating and total Ti (correlation coefficient = 0.093 (P > 0.1) nor soluble Ti (correlation coefficient = 0.009 (P > 0.1) in the soft tissue surrounding the plates. Moreover, the only independent factor of Ti release found was associated with mechanical constraints during surgery. Almost 100% of Ti is released during the osteosynthesis. Then Ti levels remain constant in the surrounding tissues. Most of the time, Ti seems to be clinically inert. Compared to the possible risks of a second operation, removal of Ti miniplates should not be a routine procedure except in the case of complaints from patients, particularly in the case of infection, hypersensitivity, dehiscence or screw loosening.

On-line reversed-phase liquid chromatography hydride generation emission spectrometry: speciation of arsenic in urine of patients intravenously treated with As2O3

Hydride generation inductively coupled plasma-atomic emission spectrometry (HG ICP-AES) was used as a continuous detection system for the determination of arsenic in the eluate from a high-performance liquid chromatographic (HPLC) system. Four arsenic species [arsenite As(III), arsenate As(V), monomethylarsonate (MMA), and dimethylarsinate (DMA)] present in the urine samples of patients treated intravenously with arsenite, were analyzed separately by HPLC-HG-ICP-AES using a non-polar C18 column. This analytical method allowed the sensitive determination of the arsenic species in the submicrogram per liter range. Urine samples collected on different days after arsenite administration were found to contain arsenite predominantly--monomethylarsonate and dimethylarsinate were also detected.

[Value and limits of determining serum cobalt levels in patients with metal on metal articulating prostheses]

PURPOSE OF THE STUDY

The purpose of this study was to measure the serum cobalt levels and their correlation with clinical and radiological findings in patients with metal on metal hip articulating surfaces.

METHOD

Forty-one patients with metal on metal hip arthroplasty were reviewed retrospectively at mean follow-up of 12.9 months. Serum cobalt levels were determined for each patient by atomic absorption spectrometry at the maximal follow-up and were compared to a control group (19 patients). Two patients and one control subjects also performed exercise on a treadmill in order to appreciate the influence of physical activity on serum cobalt levels.

RESULTS

The metal on metal group presented higher serum cobalt levels than those of the control group (p < 0.0001). There was no correlation between serum cobalt and clinical and radiological findings at the exception of patient age (n = 40, r = 0.37). However, when the follow-up was greater than 18 months, mean serum cobalt was significantly higher compared to a follow-up less than 18 months. The physical exercise test led to a moderate elevation (around 10 p. 100) of cobalt in the two patients but not in the control subject.

DISCUSSION AND CONCLUSION

The interpretation of an elevated cobalt serum level is difficult. Cobalt-containing drugs, other implants, excess of activity and diseases (renal failure) may influence serum cobalt level. In this study, the high serum cobalt levels seem not linked to a failure of the implant, mainly because of the short follow-up. They could rather be attributed to an increase of the patient activity beginning 18 months after the surgery. Because potential long-term cobalt toxicity and carcinogenicity is not well known, careful medical follow-up should be emphasized specially in young patients.

Serum LpAI lipoprotein particles in diabetic patients with and without renal lesions of different grades

Among high density lipoprotein particles, LpAI particles which contain apolipoprotein A1 alone, appear to be involved in cholesterol transport from peripheral tissues to the liver. The aim of this cross-sectional study was to examine serum LpAI particle concentrations in Type 1 and Type 2 diabetic patients with renal lesions of differing grades, in comparison with normal controls and with nondiabetic patients presenting with chronic renal failure. LpAI concentrations and LpAI-to-apo A1 ratios were increased in Type 1 diabetic patients with normal albumin excretion. In Type 1 and in Type 2 diabetic patients with increased urinary albumin excretion, LpAI concentrations and LpAI-to-apo A1 ratios were found to be not different from those of normal controls. In diabetic and in nondiabetic patients with chronic renal failure, LpAI concentrations were decreased. These abnormalities may contribute to the development of macrovascular complications.

Lipoprotein(a) in diabetic patients with and without chronic renal failure

OBJECTIVE

To examine the distribution of Lp(a) plasma levels in patients with IDDM and NIDDM, and in nondiabetic and IDDM patients with chronic renal failure.

RESEARCH DESIGN AND METHODS

Cross-sectional study of Lp(a) plasma levels in a population of diabetic patients with stable metabolic control, with simultaneous determination of plasma lipids, fasting plasma glucose, and HbA1. Thirty-six patients with IDDM, 90 with NIDDM, and 41 with chronic renal failure (20 IDDM, 21 nondiabetic) were compared with 78 control subjects.

RESULTS

Lp(a) plasma levels were significantly higher in IDDM and NIDDM patients, as well as in nondiabetic and IDDM patients with chronic renal failure compared with control subjects. No correlation was observed between Lp(a) and lipid plasma levels, fasting plasma glucose, and HbA1.

CONCLUSIONS

Lp(a) may contribute to the increased prevalence of atherosclerotic disease in diabetic patients and patients with chronic renal failure, especially in IDDM patients whose lipoprotein pattern was not different from that of the control group.

A sequential and simple determination of zinc, copper and aluminium in blood samples by inductively coupled plasma atomic emission spectrometry

A sequential method of measuring zinc, copper and aluminium in serum by inductively coupled plasma (ICP) spectrometry is described. It involves a 1/5 dilution of serum with a potassium chloride solution which enhances aluminium signal intensity and reduces variations between different matrix compositions. The method is as sensitive as atomic absorption for zinc (sensitivity: 0.11 mumol/l) and copper (sensitivity: 0.020 mumol/l) and can also be applied to monitor aluminium (sensitivity: 0.12 mumol/l) for patients receiving total nutrition therapy or hemodialysis. Its linearity extends at least to 200 mumol/l for copper and zinc and to 20 mumol/l for aluminium. The correlations with atomic absorption are satisfactory for the 3 parameters, as assessed by the correlation coefficients established for both methods. A reference interval was established with 34 sera of control subjects (19 men, 15 women) which showed an average zinc, copper and aluminium of 14.5 (S.D. 2.6), 17.3 (S.D. 2.1) and 0.32 (S.D. 0.12) mumol/l, respectively. This method does not require a simultaneous ICP spectrometer and can be performed with 1 ml of serum in a single tube, using a routine sequential ICP spectrometer.

Physiological chromium determination in serum by Zeeman graphite furnace atomic absorption spectrometry. A serious challenge

Several authors have already underlined chromium implication in glucose and lipids metabolism of humans. In this field, physiological chromium determination in serum could be helpful, but the discrepancies reported in numerous papers are confusing. Here we report some results obtained by Zeeman correction Graphite Furnace Atomic Absorption Spectrometry. This technique includes a dilution of serum with 12.5 mM ultrapure nitric acid and 0.25% Triton X-100 (final concentrations). Some main features can be outlined: (1) the contamination constitutes a serious drawback and (2) the sensitivity of the technique is critical (characteristic mass found: 1.76 pg/0.0044 A.s). Our results obtained from 27 healthy subjects (2.01 +/- 0.77 nmol/L) agree with most recent studies and indicate that serum chromium level does not seem to be sex-related.

Effect of fat-emulsion phospholipids on serum lipoprotein profile during 1 mo of cyclic total parenteral nutrition

Changes in serum lipoprotein determined by selective precipitation were investigated in 11 adult patients during 1 mo of parenteral nutrition. Patients were divided into two groups that received a similar nutrient regimen except for Intralipid (IL) phospholipid, which was higher in group A (10% IL, n = 5) than in group B (20% IL, n = 6), 139 +/- 15 vs 71 +/- 0.5 mg.kg-1.d-1 (P less than 0.01). Lipoprotein X (LPX) detected soon after IL infusions were started reached its highest concentrations in group A. LPX concentrations correlated with phospholipid intakes on days 7 and 15 but not on day 29. Significant increases in the cholesterol and phospholipid content of low-density-lipoprotein-very-low-density-lipoprotein fractions were observed only in group A. It is suggested that these changes were induced by the twofold-higher intake of phospholipids in group A. With regard to the possible involvement of LPX in lipid overloading of the reticuloendothelial system and hepatocytes, administration of 20% IL seems preferable to 10% IL.