Mercè Torra

Cadmium and zinc relationships in the liver and kidney of humans exposed to environmental cadmium

Concentrations of cadmium and zinc were determined in the liver and in the kidney (cortex and medulla) of subjects from the general population of Barcelona (Spain) by atomic absorption spectrometry. Tissues were collected from necropsies of 50 selected subjects without any occupational exposure to heavy metals. Cadmium levels calculated on a fresh tissue basis were 14.6 +/- 5.9 micrograms/g (2.4-31) in the kidney cortex, 8.6 +/- 4.3 micrograms/g (1.5-16.7) in the kidney medulla and 0.98 +/- 0.50 micrograms/g (0.32-2.32) in the liver. Zinc concentrations ranged between 18-53 micrograms/g, (mean +/- S.D.: 38.0 +/- 10 micrograms/g) in the kidney cortex, 25.0 +/- 7.7 micrograms/g (12-42 micrograms/g) in the kidney medulla and 41.7 +/- 18.3 micrograms/g (20-84 micrograms/g) in the liver. The aim of the present work was to study the association of cadmium and zinc in the kidney and in the liver of a human population with cadmium accumulation from an environmental origin. The results obtained showed a significant correlation between cadmium and zinc concentration in the liver (r = 0.86, P < 0.001), but not in the kidney.

Single-blind comparison of venlafaxine and nortriptyline in elderly major depression

The objective of this single-blind study was to compare the efficacy and safety of venlafaxine extended-release and nortriptyline in elderly patients with moderate to severe major depression. In- and out-patients (N=68) with unipolar major depression were randomized to receive 6-month treatment with either nortriptyline or venlafaxine. Outcomes of the two groups were compared using measures including the Hamilton Depression Rating Scale (HDRS) and the Newcastle Scale. Side effects were assessed with the UKU side-effect rating scale. Of the 34 venlafaxine-treated patients, 22 were remitters, 7 were nonremitters, and 5 dropped out. The intent-to-treat remission rate was 71% (22 of 31). Of the 34 who received nortriptyline, 21 were remitters, 7 were nonremitters, and 6 dropped out. The intent-to-treat remission rate was 70% (21 of 30). These results suggest that the remission rate with a therapeutic plasma level of nortriptyline is similar to the remission rate with a standard dose of venlafaxine in this group of elderly major depressed patients. No significant differences were observed between dropout rates in the two groups, but autonomic side-effects were significantly more frequent for nortriptyline than for venlafaxine. These results confirm the efficacy and safety of venlafaxine extended-release for treating elderly major depression.

Optimized procedure for lamotrigine analysis in serum by high-performance liquid chromatography without interferences from other frequently coadministered anticonvulsants

The authors have developed a simple isocratic high-pressure liquid chromatographic (HPLC) assay for the simultaneous determination of lamotrigine and other frequently coadministered antiepileptic drugs in serum samples. Lamotrigine extraction was performed on a reversed-phase Oasis HBL preparation column. The eluates containing butalbital as internal standard were separated with a 7-&mgr;m Chromsystems C18 250 × 4.0 mm I.D. reversed-phase column at a temperature of 40°C using a mobile phase consisting of pH 3.8 phosphate-acetonitrile buffer (55:45, v/v), at a flow rate of 0.8 mL/min. Ultraviolet detection was carried out at 210 nm. Measurement of the peak:height ratio allowed quantitative determination of the samples. The method was linear over a concentration range of 0.2 to 20 &mgr;g/mL for lamotrigine. Recovery was >90%. Within-day and between-day coefficients of variation ranged from 1.8% to 6.7%. The mean lamotrigine concentration was 8.01 ± 5.63 &mgr;g/mL. After studying sera from 130 patients treated with lamotrigine the authors confirmed that associated antiepileptic therapy affected the serum lamotrigine levels, which were significantly higher in patients under valproic acid treatment.

Inhibition of intratesticular testosterone synthesis by inorganic lead

The alterations in testicular testosterone synthesis produced by exposure to inorganic lead were investigated in BALB/c+ mice. Lead concentration in blood and testes and the levels of testosterone and delta 4-androgen biosynthesis pathway precursors (4-androstenedione, 17-hydroxyprogesterone, and progesterone) were measured in animals which were exposed to lead acetate in the drinking water (366 mg/l, 0.97 +/- 0.12 mg lead/animal/day) during 6 months. The results showed a significant reduction of the intratesticular testosterone levels after 30 days of exposure and of the androstenedione levels after 150 days. Intratesticular progesterone and hydroxyprogesterone levels showed no changes during the assay.

Serum and urine fluoride concentration : Relationships to age, sex and renal function in a non-fluoridated population

Serum and urine fluoride levels were determined in 250 healthy subjects (15-90 years, 122 men and 128 women) residing in Catalonia, Spain, and in 150 patients (20-81 years, 84 men and 66 women) with chronic renal failure undergoing regular dialysis treatment, living in the same geographical area, to determine normal range and to investigate its relationships to age, sex and renal function. Serum and urine fluoride were determined by a fluoride ion specific electrode system. Mean (+/- S.D.) serum fluoride concentration was 17.5 +/- 9.5 micrograms/l, ranging from 1 to 47 micrograms/l, in the control group and 58 +/- 31 micrograms/l, ranging from 28 to 185 micrograms/l, in renal patients. Urine fluoride concentration in the healthy group was 671 +/- 373 micrograms/24 h, ranging from 156 to 1900 micrograms/24 h. Fluoride status in the patient group was significantly greater than the control group. There was significant correlation between serum fluoride and age. No sex related difference was found.

Blood chromium determination in assessing reference values in an unexposed Mediterranean population.

Plasma chromium levels were determined in 243 healthy subjects. The study group consisted of 134 men and 109 women, ages 19–71 yr, all residing in Barcelona in northeastern Spain. The study was designed to assess the reference levels for plasma chromium and to investigate its relationships to age and sex. The assays were performed by means of a graphite-furnace atomic absorption spectrometer. The mean plasma chromium concentration was 3.01 ±1.45 nmol/L, ranging from 0.6 to 6 nmol/L. The upper reference values in the 0.95 percentile for this population was 5 nmol/L. No significant differences were observed with respect to the subjects’ sex.

Plasma fluoxetine concentrations and clinical improvement in an adolescent sample diagnosed with major depressive disorder, obsessive-compulsive disorder, or generalized anxiety disorder.

&NA; Fluoxetine (FLX) has been one of the most widely studied selective serotonin reuptake inhibitors in adolescents. Despite its efficacy, however, 30% to 40% of patients do not respond to treatment. Aims The aim of this study was to evaluate whether clinical improvement or adverse events are related to the corrected dose of FLX at 8 and 12 weeks after starting treatment in a sample of adolescents diagnosed with major depressive disorder, obsessive-compulsive disorder, or generalized anxiety disorder. Methods Seventy-four subjects aged between 10 and 17 years participated in the study. Clinical improvement was measured with the Clinical Global Impression–Improvement Scale, whereas the UKU (Udvalg for Klinske Undersogelser) scale was administered to assess adverse effects of treatment. Results Fluoxetine per kilograms of body weight was related to serum concentration of FLX, NORFLX (norfluoxetine), FLX + NORFLX, and FLX/NORFLX. No relationship was found between dose-corrected FLX levels and therapeutic or adverse effects. No differences in serum concentrations were found between responders and nonresponders to treatment. Sex differences were observed in relation to dose and FLX serum concentration. The analysis by diagnosis revealed differences in FLX dose between obsessive-compulsive disorder patients and both generalized anxiety disorder and major depressive disorder patients. Conclusions Fluoxetine response seems to be influenced by factors such as sex, diagnosis, or certain genes that might be involved in the drug’s pharmacokinetics and pharmacodynamics. Clinical and pharmacogenetic studies are needed to elucidate further the differences between treatment responders and nonresponders.

Synthesis of enantiopure 2-azabicyclo[3.3.1]nonanes by a radical ring closure

Abstract The first synthesis of enantiomerically pure 2-azabicyclo[3.3.1]nonanes by an intramolecular radical reaction of the trichloroacetamido group bearing an ( S )- N -1-phenylethyl substituent with the silyl enol ether moiety in compounds 7 is described. The procedure allows the two enantiomers of the 2-azabicyclo[3.3.1]nonane-3,6-dione, 3 and ent - 3 , to be prepared separately. β-Lactam 8 and normorphan 9 are also formed from 7 through an initial radical translocation process in the cyclization step.

Serum and urine ionic fluoride: normal range in a nonexposed population.

The present study was undertaken to evaluate the fluoride status in the general healthy population of Barcelona. Serum and urine fluoride ionic concentration was determined in a random sample of 250 subjects (age range 15–90 yr) by the Orion fluoride electrode system to determine the normal range of fluoride in this population. The results obtained show that in the general population of Barcelona, fluoride ionic serum concentration ranges between 1 and 47 μg/L (x = 17.5 ± 9.7 μg/L) and fluoride ionic urine concentration ranges between 156 and 1990 μg/24 h (x = 671 ± 373 μg/24 h). The mean serum fluoride concentration of the younger population was shown to be significantly greater (p < 0.05) than that of the older group. No sex-related difference was found.

Acute oxcarbazepine overdose in an autistic boy

Oxcarbazepine (OXC), a 10-keto analogue of carbamazepine, is an antiepileptic drug licensed for the treatment of partial seizures in children and adults, as monotherapy or adjunctive therapy [1]. In humans, OXC is rapidly metabolized in liver to 10-monohydroxy-carbazepine (MHD), its active metabolite. MHD blocks voltage-sensitive sodium channels, stabilizing hyperexcited neuronal membranes, thereby inhibiting repetitive firing and decreasing the propagation of synaptic impulses [2]. Recently, successful use of OXC in the management of disruptive behaviours in autistic patients has also been reported [3].