Expression of TWEAK and its receptor Fn14 in human subcutaneous adipose tissue. Relationship with other inflammatory cytokines in obesity

TWEAK, a cytokine of the TNF family, has been found to be expressed under different inflammatory conditions but no data is available concerning the expression of this cytokine and its receptor (Fn14) in human obesity. In the present work we have evaluated the expression of many pro-inflammatory TNF system cytokines (TNF-alpha, TWEAK and their respective receptors, TNFR1, TNFR2 and Fn14) in human adipose tissue of 84 subjects some with different degree of obesity and type 2 diabetes, and its relation with inflammation by also measuring the expression of macrophage marker CD68. We detected expression of TWEAK and Fn14 in isolated mature adipocytes and in the stromovascular fraction. Additionally, we found that LPS upregulates the expression of both genes on THP-1 human monocytic cell line. TWEAK was expressed in adipose tissue of all studied subjects with no differences between obesity group, and was associated with Fn14 expression in morbid obese, mainly in women with type 2 diabetes. The data obtained here also showed that TNF-alpha and TNFR2 mRNAs were significantly more expressed in subcutaneous adipose tissue of subjects with morbid obesity compared to obese and non-obese subjects. In contrast, TNFR1 gene expression was negatively associated with BMI. Our results suggest that the expression of TNF-derived pro-inflammatory cytokines are increased in severe obesity, where macrophage infiltrate could modulate the inflammatory environment through activation of its receptors.

[Unusual variants of Guillain-Barré syndrome in infancy]

AIMS

To identify unusual variants within a paediatric population of patients with Guillain-Barré syndrome (GBS), to determine the frequency of their occurrence and to describe their clinical and electrophysiological characteristics.

PATIENTS AND METHODS

The medical records of 179 patients diagnosed with GBS were reviewed. Those who strictly satisfied the Asbury criteria were excluded.

RESULTS

Twenty patients, with a mean age of 7.6 years at the onset of symptoms, presented the following clinical variants: multiple cranial polyneuropathy (4 cases), Miller Fisher syndrome (MFS) (3 cases), pharyngeal-cervical-brachial palsy (PCBP) (2 cases), combined MFS and PCBP (3 cases), paraparesis (4 cases), palpebral ptosis without ophthalmoplegia (1 case), ophthalmoplegia without ataxia (1 case), paresis of the abducent nerve with paresthesias (1 case), and saltatory (1 case). Albuminocytologic dissociation was reported in 77.8% of patients and neuroconduction with a demyelinating pattern was noted in 75%. Patients progressed favourably in 94.4% of cases.

CONCLUSIONS

In our study, 11.2% of a population of children with GBS presented unusual variants and did not meet the criteria established by Asbury et al. Recognising these variants of GBS in patients with complex pictures such as those described here enables therapy to be established quickly. The question remains as to whether these variants represent a clinical response to different antibodies or to a regional susceptibility of the host.

Available lysine content in human milk: stability during manipulation prior to ingestion

Available lysine content is an indicator of protein quality and nutritional value of milk. Many studies have examined the effects of extraction, treatment and storage of human milk upon its components, though no references are found regarding the possible changes in milk quality as defined by its content in essential amino acids such as lysine. The present study investigates the available lysine content in human milk and the variations in lysine resulting from milk manipulation as follows: (a) Cold storage (refrigeration at 4 degrees C for 48 hours, and frozen for 15 days at -20 degrees C); (b) Thermal treatment under conditions of low (Holder)(63 degrees C/30 minutes) and high pasteurization (75 degrees C/15 seconds). The results obtained show a decrease in milk lysine concentration after storage in both refrigerated and frozen samples. Pasteurization causes a highly significant loss of available lysine. The lysine losses were greater on applying low pasteurization versus the more gentle conditions of high pasteurization.

CONCLUSIONS

While manipulation through cold storage or thermal treatment does not affect the protein content of human milk, its protein quality is modified. When human milk must be subjected to hygienization, it is preferable to apply high temperature treatment (75 degrees C, 15 seconds) than habitual pasteurization (63 degrees C, 30 minutes).

Primary Sjogren's syndrome presenting as a generalized chorea

We report on a patient who presented with generalized chorea as the first manifestation of Sjogren Syndrome, and review the possible pathogenesis.

Effects of moderate pollution on toxic and trace metal levels in calves from a polluted area of northern Spain

This study evaluated the contribution of anthropogenic pollution to toxic metal residues (Cd, Pb and As) in cattle in an industrialized area of Asturias (northern Spain), and investigated possible implications of toxic metal exposure for metabolism of essential metal elements (Cu, Zn, Fe, Mn). Samples of liver, kidney, muscle and blood from animals aged 9-12 months were obtained from an industrialized area (78 calves) and from a rural area (92 calves). Samples were acid-digested, and levels of metals determined by atomic absorption spectrophotometry. Cadmium and lead contents in the liver and kidney were moderately and significantly higher in calves from the industrialized area (Cd: liver 29.6, kidney 161; Pb: liver 38.1, kidney 38.3 microg/kg wet weight) than in calves from the rural area (Cd: liver 22.9, kidney 96.4; Pb: liver 20.7, kidney 15.9 microg/kg kg wet weight). Although these toxic metals were only moderately raised, our results suggest that they may nevertheless have interfered with trace element metabolism, as reported previously for severely polluted regions. Notably, copper levels in calves from the industrialized area were generally low, and nearly half of these animals showed tissue copper levels indicating risk of copper deficiency.

The role of metallothionein and zinc in hepatic copper accumulation in cattle

The role of metallothionein (MT) and zinc (Zn) in hepatic copper (Cu) accumulation in calves from a region in North-West Spain has been investigated. In this region there is intensive pig farming, and animals with liver Cu concentrations above normal are not uncommon. Concentrations of hepatic MT were not related to Cu accumulation but were strongly dependent on the Zn status of the animal. When analysing the metal content bound to MT it was observed that Cu-MT values, in the same way as Zn-MT, were directly correlated with MT concentrations in the liver, indicating that although Cu is a poor inducer of MT synthesis, it can compete with Zn for MT binding sites. The ability of Cu to displace Zn from MT is highly dependent on the Cu:Zn ratio in the cell, Cu being the main metal in MT at the higher levels of Cu exposure in Galician cattle. In spite of this, the percentage of the total hepatic Cu bound to MT is very low in these animals, indicating that cattle have a very limited capacity to accumulate Cu-MT in the liver, and may therefore have a greater susceptibility to Cu toxicosis.

[Oxidative stress in a model for experimental diabetic retinopathy: treatment with antioxidants]

PURPOSE

Diabetic retinopathy is the primary cause of blindness in developed countries, and though strict glycemic control is desirable to prevent complications, this is not always achievable. Thus, adjunctive therapies are needed to help in preventing or delaying the onset of diabetic complications. We have studied the biochemical and functional changes in the retina of diabetic mice, and the ability of ebselen and lutein, two antioxidants, to reverse these effects, using as a comparison the effect of insulin therapy.

METHODS

Alloxan injection was used to achieve hyperglycemia. Malondialdehyde (MDA) concentration in blood and glutathione peroxidase (GPx) activity in eye homogenate were measured. Serial electroretinograms (ERG) were recorded.

RESULTS

MDA concentration in the blood was high in diabetic animals. GPx activity in eye homogenate decreased in the diabetic conditions. Maximal electroretinogram amplitude decreased in diabetic animals with respect to controls. Ebselen and lutein restored MDA levels, GPx activity and ERG amplitude, and had no effect on glycemia.

CONCLUSION

These results call for further studies on ebselen or lutein as adequate adjunctive therapies for diabetes.

Oral contraceptive induced chorea: another condition associated with anti-basal ganglia antibodies

Use of oral contraceptives is a recognised but infrequent cause of chorea. This type of chorea has usually been considered a reactivation of Sydenham's chorea by an unknown mechanism. A patient developed a chorea triggered by the use of oral contraceptives with no definite evidence of previous Sydenham's chorea or recent streptoccocal infections. However, the patient had positive anti-basal ganglia antibodies, which supports an immunological basis for the pathophysiology of this chorea.

Values of plasma lipid hydroperoxides and total antioxidant status in healthy dairy cows: preliminary observations

Abstract. Metabolic parameters have been used in an attempt to monitor the health, reproductive and nutritional status of dairy cows. Nevertheless, in the last few years the detection of free radical damage, and the protection against it has become very important in the practice of clinical medicine. This report aims to establish values for plasma lipid hydroperoxides (LOOH) and total antioxidant status (TAS) in healthy cows and its relationship with milk yield. The study was carried out with 22 healthy dairy cows divided into two groups: animals with a low production rate and animals with a high milk yield. Results showed that the animals with a high milk yield present higher LOOH levels than the other group. This increase in oxidant compounds is not accompanied by higher levels in protective antioxidant substances. LOOH and TAS measurements give complementary information about the metabolic status of the animal than metabolic parameters alone.

Cadmium and lead accumulation in cattle in NW Spain

This study investigated if differences in nutritional management (linked to feed composition and feed intake) could determine differences in the toxic metal accumulations in beef and dairy cattle in NW Spain. Cadmium and lead concentrations were determined in the liver, kidney and muscle of 57 cows (3-16 y-o) by inductively coupled plasma optical emission spectroscopy. Dairy cattle accumulated significantly higher cadmium and lead residues in liver (51.6 and 43.7 microg/kg fresh weight) than did beef cattle (35.7 and 14.7 microg/kg). In the kidney and muscle, cadmium and lead residues were similar in both dairy and beef cattle. The higher metal accumulations in the liver of dairy cattle could be related not only to higher dietary intake, but also to the higher hepatic metabolism associated with milk production.

Mercury concentrations in cattle from NW Spain

Mercury is a toxic metal that is released into the environment as a result of various industrial and agricultural processes. It can be accumulated by domestic animals and so contaminate human foodstuffs. To date, there is no information on mercury residues in livestock in Spain and the aim of the present study was to quantify the concentrations of mercury in cattle in two of the major regions in north-west Spain, Galicia (a largely rural region) and Asturias, which is characterised by heavy industry and mining. Total mercury concentrations were determined in tissue (liver, kidney and muscle) and blood from 284 calves (6-10 months old) and 56 cows (2-16 years old) from across the whole of the two regions. Mercury was usually detected in the kidney (62.4-87.5% of samples) but most (79.5-96%) liver, muscle and blood samples did not contain detectable residues. Renal mercury concentrations did not differ between male and female calves but were significantly greater in female calves than in cows. Unexpectedly, kidney mercury concentrations were significantly higher in calves from the predominantly rural region of Galicia (geometric mean: 12.2 microg/kg w.wt.) than in animals from the industrialised-mining region of Asturias (3.40 microg/kg w.wt.). Overall, mercury residues in cattle from NW Spain were similar to those reported in cattle from non-polluted areas in other countries and do not constitute a risk to animal or human health.

Large-scale spatial variation in mercury concentrations in cattle in NW Spain

Mercury (Hg) is a highly toxic environmental contaminant and man-made emissions account for between a quarter and a third of total atmospheric levels. Point discharges, particularly coal-burning power stations, are major sources of atmospheric Hg and can result in marked spatial variation in mercury deposition and subsequent uptake by biota. The aims of this study were to quantify the extent to which major point and diffuse sources of atmospheric Hg emissions affected accumulation of Hg by biota throughout Galicia and Asturias, two of the major regions in northwest Spain. We did this by relating renal Hg concentrations in locally reared cattle (n=284) to the proximity of animals to point and diffuse sources of Hg emissions. Mercury residues in calf kidneys ranged between non-detected and 89.4 g/kg wet weight. Point discharges from coal-fired power plants in Galicia had the most dominant impact on Hg accumulation by calves in Galicia, affecting animals throughout the region and explaining some two-thirds of the variation in renal residues between animals located directly downwind from the plants. The effects of more diffuse emission sources on Hg accumulation in calves were not distinguishable in Galicia but were detected in cattle from neighbouring Asturias. The impact of both point and diffuse sources in elevating environmental levels of bioavailable Hg and subsequent accumulation by cattle extended to approximately 140-200 km downwind from source.

Cattle as biomonitors of soil arsenic, copper, and zinc concentrations in Galicia (NW Spain)

Determination of soil concentrations of trace and pollutant metals over large spatial areas requires laborious and expensive sampling effort. In this study, we examined the feasibility of using calves as biomonitors of soil semimetal and trace metal concentrations in Galicia (NW Spain), a region in which calves are predominantly reared on grass or locally grown forage. We determined the concentrations of arsenic, copper, and zinc in the liver, kidney, muscle, and blood of calves from across Galicia and related them to the metal concentrations in the soil from the areas in which the animals were reared. For each element, liver (but not usually kidney, muscle, or blood) concentrations were significantly elevated in animals from areas with higher soil concentrations. Liver arsenic concentrations were only markedly greater in animals from areas with soil arsenic levels > 20 mg/kg, and calves may not be sensitive enough biomonitors of background variation in soil levels, although they may be useful for monitoring anthropogenic arsenic contamination. Copper and zinc liver levels increased progressively with soil levels, and the pattern was especially marked for copper. The relatively unusual copper metabolism of cattle and other ruminants may make them particularly good biomonitors for environmental concentrations of this metal.

Chronic eosinophilic leukaemia presenting with erythroderma, mild eosinophilia and hyper-IgE: clinical, immunological and cytogenetic features and therapeutic approach. A case report

A 23-year-old, white male metallurgist presented with pruritic erythematous maculo-papules over the trunk and upper limbs and 6 months later developed erythroderma, eosinophilia and multi-organ dysfunction. A diagnosis of chronic eosinophilic leukaemia was made on the basis of myeloproliferative involvement of both peripheral blood and bone marrow, associated with eosinophilic differentiation and a t(5;12)(q33;p13) translocation. The initial therapeutic approach was interferon alfa-2b plus cytosine arabinoside, for 13 months, followed by hydroxyurea plus vincristine. There was improvement of skin lesions, disappearance of eosinophilia and decrease of serum immunoglobulin E, towards normal values.

Contribution of cattle products to dietary intake of trace and toxic elements in Galicia, Spain

In Galicia, Spain, liver copper concentrations, muscle zinc concentrations and kidney cadmium concentrations (in adult cattle) can exceed acceptable maximum concentrations which have been adopted by some countries. The aim was to calculate the contribution of cattle products to the daily intake of trace and toxic metals by humans in Galicia and to evaluate whether there was any health risk to consumers. This was done by comparing calculated intakes with published acceptable daily intake rates for toxic elements and with the accepted safe ranges for population mean intakes of the essential metals. Typically, the contribution of cattle meat and offal to the daily cadmium, lead and arsenic intake of people in Galicia was minimal because offal is rarely eaten. However, liver from older cattle, especially animals from relatively contaminated areas, could pose a health risk if offal was consumed in substantial quantities. Muscle and liver from Galician cattle that exceeded acceptable maximum concentrations for copper and zinc did not pose a risk to human health.

Interactions between toxic and essential trace metals in cattle from a region with low levels of pollution

Studies on the impacts of pollutant metals and metalloids on livestock have largely focused on animals with relatively high levels of exposure. The impact of low-level environmental contamination, which is more common on agricultural land, is largely unknown. The principal aim of the present study was to examine the effects of low-level environmental contamination on trace metal metabolism in cattle from the rural and relatively uncontaminated region of Galicia (NW Spain). Correlations between toxic (cadmium, lead, and arsenic) and essential trace elements (copper and zinc) were evaluated in the tissues (liver, kidney, and muscle) and blood of 494 cattle from throughout Galicia. Cadmium was the toxic element that had the greatest influence on copper and zinc homeostasis. There was a significant positive association between renal cadmium and zinc residues and a significant negative correlation between kidney cadmium and copper. These interactions are likely to be the result of cadmium-induced effects on metallothionein synthesis. Lead and zinc were positively associated in the kidney, although the mechanism of this interaction is uncertain. Arsenic and copper concentrations were strongly correlated with each other in the liver and may indicate that the high copper levels in animals from copper-rich areas in Galicia interfere with their arsenic excretion. The essential metals copper and zinc were also significantly associated with each other in calves but not in cows.

Allogeneic stem cell transplantation for Evans syndrome

Evans syndrome is a rare disorder characterized by combined autoimmune thrombocytopenia (ITP) and autoimmune hemolytic anemia (AIHA). Standard treatments consist of transfusions, corticosteroids, splenectomy, IVIG, anabolic steroids, vincristine, alkylating agents, or cyclosporine. In a patient with refractory disease, an allogeneic hematopoietic stem cell transplant (HSCT) resulted in complete clinical and serologic remission for more than 30 months. Allogeneic HSCT may be the only current curative therapy for Evans syndrome but may also be complicated by significant toxicities.

Morphofunctional mitochondrial response to methylglyoxal toxicity in Bufo bufo embryos

Methylglyoxal (2-oxopropanal) is a reactive alpha-oxoaldehyde that can be formed endogenously mainly as a by-product of glycolytic pathway. It is a cytotoxic compound with significant antiproliferative properties as it can bind, under physiological conditions, to nucleic acids and proteins, forming stable adducts. We have recently shown that exogenous methylglyoxal (150-600 microM) is highly toxic for amphibian embryos where it produces, when added to the culture water, inhibition of cell proliferation in the early developmental stages, followed by severe malformations and strongly reduced embryonic viability. In this work we investigate the morphofunctional effect of methylglyoxal on the common toad B. bufo embryo mitochondria in order to verify if its dysmorphogenetic action might be also ascribed to impairment of mitochondrial functions. The mitochondria were isolated from embryos at the developmental stages of morula, neural plate and operculum complete and developing in the presence of 600 microM methylglyoxal. The results show that exogenous methylglyoxal is highly toxic at mitochondrial level, where it produces proliferation, swelling and membrane derangement. As a consequence, mitochondria from treated embryos show decreased oxidative phosphorylation efficiency, as indicated by the significant reduction both of the respiratory control index values and of the embryonic ATP content. On the basis of these data, it is possible that the methylglyoxal-induced embryonic malformations as well as the strongly reduced viability might be also ascribed to energy depletion.

A Different Point of View of Glutathione Peroxidase: its Relationship to the Metabolic Changes Associated with Nutritional Management in Assaf ovine breed

Abstract. We considered the role played by selenium-dependent glutathione peroxidase (GSH-Px) in relation to the metabolic changes due to nutritional management in a flock of the Assaf breed in Spain, housed in an intensive management system. Our objective was to examine the relationship between the nutritional management of this flock during different productive stages and GSH-Px. The modifications of ASAT and CK activities, closely connected to the pathological changes in GSH-Px values, were also recorded. The animals were divided into two groups: control and experimental ewes. Our results showed that neither physiological condition nor litter size had any influence on the GSH-Px values; the main modifications were due to the diet of these animals, especially if the diet was rieh in essential fatty acids. The evolution of ASAT and CK activities, and their relationship to GSH-Px and nutrition, is also described.

Amino acid permeases in developing seeds of Vicia faba L.: expression precedes storage protein synthesis and is regulated by amino acid supply

Full length cDNAs encoding three amino acid permeases were isolated from seed-specific libraries of Vicia faba. The predicted proteins VfAAP1, VfAAP3 and VfAAP4 share up to 66% identity among themselves. Functional characterization of VfAAP1 and VfAAP3 in a yeast mutant showed that these permeases transport a broad range of amino acids. However, VfAAP1 had a preference for cysteine and VfAAP3 for lysine and arginine. VfAAP1 was highly expressed in cotyledons at early developmental stages and moderately in other sink tissues. Its peak of expression in cotyledons corresponded to the appearance of storage protein transcripts, suggesting that this transporter fulfills an important role in providing amino acids for storage protein biosynthesis. VfAAP3 was expressed most abundantly in maternal tissues, that is in roots, stems, gynoecia, pods and seed coats at different developmental stages. VfAAP4 transcripts could not be detected by northern hybridization. In situ hybridization showed that VfAAP1 mRNA is distributed throughout cotyledon storage parenchyma cells, but could not be detected in the abaxial epidermal cell layer. It also accumulate in the chlorenchyma and thin-walled parenchyma cells of seed coats. VfAAP1 mRNA levels were lower in cotyledons cultured in the presence of glutamine, whereas expression of a vicilin storage protein gene was up-regulated under similar conditions. Cysteine repressed the expression of the GUS reporter gene under control of the VfAAP1 promoter, suggesting that this transporter is modulated at the transcriptional level. Regulation of amino acid transport in relation to storage protein accumulation is discussed.

[Chronic hepatic encephalopathy: the role of high serum manganese levels and its relation with basal ganglia lesions in nuclear magnetic resonance of the brain. Clinical case]

Chronic hepatic encephalopathy (CHE) is a disabling complication of chronic liver failure and porto-systemic shunt. The pathogenesis of CHE remains unclear but increased levels of ammonia are a basic feature. Several clinical and experimental observations support a role for manganese (Mn) in the pathogenesis of this disorder. Increased blood levels of Mn have been described in patients with CHE and this could lead to its accumulation on the basal ganglia and characteristic hyperintensities of basal ganglia as seen on magnetic resonance imaging (MRI) of the brain. We report on the clinical features and characteristic radiologic findings of a patient who presented with the neurologic syndrome of CHE and who had very high blood levels of Mn in the absence of an occupational exposure to this metal. Our report supports the hypothesis that Mn has a role in the pathogenesis of CHE and also suggests that brain MRI is a useful marker of the brain metabolic repercussion due to CHE.

The Chilean version of the Childhood Health Assessment Questionnaire (CHAQ) and the Child Health Questionnaire (CHQ)

We report herein the results of the cross-cultural adaptation and validation into the Chilean language of the parent's version of two health related quality of life instruments. The Childhood Health Assessment Questionnaire (CHAQ) is a disease specific health instrument that measures functional ability in daily living activities in children with juvenile idiopathic arthritis (JIA). The Child Health Questionnaire (CHQ) is a generic health instrument designed to capture the physical and psychosocial well-being of children independently from the underlying disease. The Chilean CHAQ-CHQ were derived from the European Spanish version with changing of the few words whose use is different in the 2 countries. A total of 126 subjects were enrolled: 72 patients with JIA (29% systemic onset, 39% polyarticular onset, 4% extended oligoarticular subtype, and 28% persistent oligoarticular subtype) and 54 healthy children. The CHAQ clinically discriminated between healthy subjects and JIA patients, with the JIA patients having a higher degree of disability, pain, and a lower overall well-being when compared to their healthy peers. Also the CHQ clinically discriminated between healthy subjects and JIA patients, with the JIA patients having a lower physical and psychosocial well-being when compared to their healthy peers. In conclusion the Chilean version of the CHAQ-CHQ is a reliable, and valid tool for the functional, physical and psychosocial assessment of children with JIA.

Stalk segment 5 of the yeast plasma membrane H+-ATPase: mutational evidence for a role in glucose regulation

In P(2)-type ATPases, a stalk region connects the cytoplasmic part of the molecule, which binds and hydrolyzes ATP, to the membrane-embedded part through which cations are pumped. The present study has used cysteine scanning mutagenesis to examine structure-function relationships within stalk segment 5 (S5) of the yeast plasma-membrane H(+)-ATPase. Of 29 Cys mutants that were made and examined, two (G670C and R682C) were blocked in biogenesis, presumably due to protein misfolding. In addition, one mutant (S681C) had very low ATPase activity, and another (F685C) displayed a 40-fold decrease in sensitivity to orthovanadate, reflecting a shift in equilibrium from the E(2) conformational state toward E(1). By far the most striking group of mutants (F666C, L671C, I674C, A677C, I684C, R687C, and Y689C) were constitutively activated even in the absence of glucose, with rates of ATP hydrolysis and kinetic properties normally seen only in glucose-metabolizing cells. Previous work has suggested that activation of the wild-type H(+)-ATPase results from kinase-mediated phosphorylation in the auto-inhibitory C-terminal region of the 100-kDa polypeptide. The seven residues identified in the present study are located on one face of the S5 alpha-helix, consistent with the idea that mutations along this face serve to release the auto-inhibition.

[Polyneuropathy in critically ill patients: a seldom recognized cause of dependence on mechanical ventilators]

INTRODUCTION

Neuromuscular complications, in a critical care unit, are a cause of morbidity in children and prolonged dependence on a mechanical ventilator. Polyneuropathy of the critical patient is such a complication and is seen in patients on mechanical respiratory assistance.

OBJECTIVE

To discuss the neurological and electrophysiological clinical findings of polyneuropathy of the critical patient.

CLINICAL CASE

We evaluated four patients who initially required mechanical respiratory assistance, three for lung disorders and one for acute encephalopathy, who developed prolonged dependence on mechanical ventilators in the year 1999. In all these patients electromyography showed primary axon nerve disorders with secondary demyelination of all four limbs and phrenic nerve involvement.

CONCLUSIONS

Clinical suspicion and use of suitable electrophysiological techniques permits identification of this condition in the severely ill paediatric patient. Better recognition of the condition and investigation of the etiological factors would help to develop suitable measures for prevention and treatment.

Developmental expression and distribution of amphibian glutathione transferases

This work is aimed at detecting the expression and location of embryonic Bufo bufo GST (bbGSTP1-1) and adult B. bufo GST (bbGSTP2-2) during toad development, in order to assign a putative role to these enzymes also on the basis of their compartmentalization and to verify whether during the premetamorphic liver ontogeny the bbGSTP2-2 form appears. This study was also performed in the adult liver (the primary site of Pi class GST expression) and in the mature ovary, to discern if the embryonic form derives from maternal form. The results show that the embryos and the ovary express only bbGSTP1-1. Moreover, bbGSTP1-1 distribution is the same both in the early embryos and in the ovary: this strongly suggests that bbGSTP1-1 is of maternal origin. As development goes on, a wide distribution of bbGSTP1-1 all over the differentiating organs is observed. The embryonic liver expresses exclusively the bbGSTP1-1 form, while the adult liver is highly positive only towards the bbGSTP2-2 form. This implies that the switch towards the adult bbGSTP2-2 form occurs in metamorphic or postmetamorphic phases and that the detoxication metabolic requirements of the embryo may be completely fulfilled by the bbGSTP1-1 isoenzyme.

The effect of mussel size, temperature, seston volume, food quality and volume-specific toxin concentration on the uptake rate of PSP toxins by mussels (Mytilus galloprovincialis Lmk)

The accumulation of paralytic shellfish poisoning (PSP) toxins by bivalves is a serious threat to public health all over the world. However, very little is known about the uptake kinetics of these toxins and the environmental factors that may modify this process. We have studied the effect of mussel size, temperature, seston volume, food quality, and volume-specific toxin concentration (VOSTOC), on the uptake rate of paralytic shellfish poisoning (PSP) toxins by mussels (Mytilus galloprovincialis), by means of a second order factorial experiment. Over a 3-day period, the mussels were fed artificial diets containing Alexandrium minutum AL1V (a PSP toxin producer), Tetraselmis suecica, Ensiculifera sp1 and silt, to the levels required by each treatment. Mussel size, seston volume and VOSTOC were found to be statistically significant when the total toxin accumulated per weight of wet tissue was considered. Mussel size affected the uptake negatively and latter two positively. The interactions, mussel size-VOSTOC and mussel size-food quality were also significant. The response was not linear as shown by the significance of the quadratic term of mussel size. Notwithstanding, when the PSP toxins accumulation per mussel was analysed, only one factor, the VOSTOC and the interactions, food quality-mussel size and food quality-seston volume, were found to be significant. VOSTOC was the most important factor in the accumulation of toxins, in our opinion, probably due to toxin assimilation being mainly regulated by the probability of contact between the toxins and the cellular walls of the digestive system. The size of the bivalve is also especially important because toxin concentration is usually calculated per weight of bivalve tissue and because the weight-specific ingestion increases with mussel size. The food quality, which was directly related to the assimilation of organic matter, had an inverse effect on toxin assimilation. In our opinion, this is probably due to the effect of inorganic particles in enhancing the disruption of Alexandrium cells. Temperature had no effect on the uptake rate except for the accumulation of the gonyautoxin GTX1.

[Restless legs syndrome: a clinical study in adult general population and in uremic patients]

BACKGROUND

The restless legs syndrome (RLS) is a movement disorder characterized by an imperative urge to move the legs, associated with paraesthesias, motor restlessness and worsening of symptoms at night with at least partial relief by activity. Its prevalence ranges between 2-15% of general adult population and 20-30% of uremic patients.

AIM

To evaluate the frequency and the clinical features of RLS in a sample of general adult population and in uremic patients, in Chile, correlating it with biochemical parameters.

METHOD

100 relatives of outpatients and 166 uremic patients undergoing chronic haemodialysis were interviewed assessing the presence and severity of RLS according to current diagnostic criteria. Biochemical parameters assessed were hematocrit, serum ferritin, phosphate, intact parathyroid hormone (iPTH) levels.

RESULTS

13% of the general population sample was affected, 15% of them were severe. Forty three cases were found among uremic patients (25.9%) (p < 0.01 vs general population), 60% of them were severe and women were affected with higher frequency (p < 0.05) and severity (p < 0.01). Four patients presented RLS even during hemodialysis. No correlation was found with biochemical parameters. Most RLS cases had not been diagnosed previously.

CONCLUSIONS

In our population RLS is common and undetected. It is especially prevalent and severe in uremic patients: we found no evidence that anaemia, iron deficiency or iPTH level play a major pathogenic role. Our findings emphasize the need of greater medical awareness of RLS because available therapy may improve the quality of life.

Sequence and analysis of chromosome 1 of the plant Arabidopsis thaliana

The genome of the flowering plant Arabidopsis thaliana has five chromosomes. Here we report the sequence of the largest, chromosome 1, in two contigs of around 14.2 and 14.6 megabases. The contigs extend from the telomeres to the centromeric borders, regions rich in transposons, retrotransposons and repetitive elements such as the 180-base-pair repeat. The chromosome represents 25% of the genome and contains about 6,850 open reading frames, 236 transfer RNAs (tRNAs) and 12 small nuclear RNAs. There are two clusters of tRNA genes at different places on the chromosome. One consists of 27 tRNA(Pro) genes and the other contains 27 tandem repeats of tRNA(Tyr)-tRNA(Tyr)-tRNA(Ser) genes. Chromosome 1 contains about 300 gene families with clustered duplications. There are also many repeat elements, representing 8% of the sequence.

The effect of pig farming on copper and zinc accumulation in cattle in Galicia (north-western Spain)

Copper and zinc are frequently added at high concentrations to pig diets as growth promoters. Livestock grazing pasture contaminated with pig slurry may, therefore, be at risk from excessive intake of these elements. High liver copper concentrations have been detected in cattle from the agricultural region of Galicia (NW Spain), especially where there is intensive pig farming. The aim of this study was to evaluate whether pig farming does affect accumulation of copper and zinc in cattle in Galicia. Hepatic copper and zinc concentrations in calves were elevated in areas with naturally high levels of these elements in the soil. The densities of young pigs (piglets and growing-finishing pigs), but not reproductive sows, also influenced copper accumulation in calves. Liver copper levels in calves were significantly and positively related to the density of young pigs in the region. In areas with the highest pig densities, more than 20% of the cattle analysed had hepatic copper concentrations that exceeded the potentially toxic concentration of 150 mg/kg fresh weight. There was no evidence that zinc accumulation in calves was affected by pig density.

Effect of sex on arsenic, cadmium, lead, copper and zinc accumulation in calves

This study evaluated the effect of sex on the accumulation of arsenic, cadmium, lead, copper and zinc in calves. Samples of liver, kidney, muscle and blood of 312 animals (127 females and 185 males) were analysed after acid digestion using atomic absorption spectrophotometry (AAS). Arsenic was determined by AAS interfaced with continuous flow hydride generation, cadmium and lead by graphite furnace, and copper and zinc by flame. Females accumulated more cadmium, copper and zinc in kidneys than did males. The zinc blood levels in females were higher than in males, whereas copper in liver was higher in males than in females. In the case of arsenic and lead, no significant statistical differences between males and females were found.

Antioxidant and GSH-related enzyme response to a single teratogenic exposure to the anticonvulsant phenytoin: temporospatial evaluation

BACKGROUND

It has been proposed that the anticonvulsant drug phenytoin (PHT) requires bioactivation to reactive intermediate(s) to achieve its recognized teratogenic potential and that embryonal detoxification power may play a fundamental role in the teratogenic response. On this basis, we sought to investigate the potential effects of a teratogenic exposure to PHT on the activities of antioxidant and GSH-related detoxifying enzymes in gestational murine tissues.

METHODS

Pregnant Swiss mice were injected intraperitoneally with 0 (vehicle) or 65 mg/kg of PHT on gestation day (GD) 12 (plug day = GD 1). Biochemical determinations, including activities of glutathione transferase, glutathione peroxidase, glutathione reductase, glyoxalase I, glyoxalase II, catalase, and superoxide dismutase, were carried out on maternal and embryonic/fetal livers and in placentas on GD 14 and 19.

RESULTS

The major findings of this study show that (1) organogenesis-stage conceptal tissues have detectable levels of all the tested enzymes; (2) most of the embryonic liver and placental enzymes investigated undergo a significant induction within 48 hr (GD 14) after PHT administration; and (3) in the same tissues a down-regulation of enzyme activities is noted near term (GD 19).

CONCLUSIONS

Overall, these findings show that teratogenic exposure to PHT is associated with a modulation of reactive-intermediates-scavenging enzyme activities, and provide further support for role of generation of reactive intermediates in PHT-induced teratogenesis.

Stalk segment 4 of the yeast plasma membrane H+-ATPase. Mutational evidence for a role in the E1-E2 conformational change

In the P(2)-type ATPases, there is growing evidence that four alpha-helical stalk segments connect the cytoplasmic part of the molecule, responsible for ATP binding and hydrolysis, to the membrane-embedded part that mediates cation transport. The present study has focused on stalk segment 4, which displays a significant degree of sequence conservation among P(2)-ATPases. When site-directed mutants in this region of the yeast plasma membrane H(+)-ATPase were constructed and expressed in secretory vesicles, more than half of the amino acid substitutions led to a severalfold decrease in the rate of ATP hydrolysis, although they had little or no effect on the coupling between hydrolysis and transport. Strikingly, mutant ATPases bearing single substitutions of 13 consecutive residues from Ile-359 through Gly-371 were highly resistant to inorganic orthovanadate, with IC(50) values at least 10-fold above those seen in the wild-type enzyme. Most of the same mutants also displayed a significant reduction in the K(m) for MgATP and an increase in the pH optimum for ATP hydrolysis. Taken together, these changes in kinetic behavior point to a shift in equilibrium from the E(2) conformation of the ATPase toward the E(1) conformation. The residues from Ile-359 through Gly-371 would occupy three full turns of an alpha-helix, suggesting that this portion of stalk segment 4 may provide a conformationally active link between catalytic sites in the cytoplasm and cation-binding sites in the membrane.

Aldosterone- and testosterone-mediated intracellular calcium response in skeletal muscle cell cultures

Fast nongenomic steroid actions in several cell types seem to be mediated by second messengers such as intracellular calcium ([Ca(2+)](i)) and inositol 1,4,5-trisphosphate (IP(3)). We have shown the presence of both slow calcium transients and IP(3) receptors associated with cell nuclei in cultured skeletal muscle cells. The effect of steroids on [Ca(2+)](i) was monitored in Fluo 3-acetoxymethyl ester-loaded myotubes by either confocal microscopy or fluorescence microscopy, with the use of out-of-focus fluorescence elimination. The mass of IP(3) was determined by radioreceptor displacement assay. [Ca(2+)](i) changes after either aldosterone (10-100 nM) or testosterone (50-100 nM) were observed; a relatively fast (<2 min) calcium transient, frequently accompanied by oscillations, was evident with both hormones. A slow rise in [Ca(2+)](i) that reached its maximum after a 30-min exposure to aldosterone was also observed. Calcium responses seem to be fairly specific for aldosterone and testosterone, because several other steroid hormones do not induce detectable changes in fluorescence, even at 100-fold higher concentrations. The mass of IP(3) increased transiently to reach two- to threefold the basal level 45 s after addition of either aldosterone or testosterone, and the IP(3) transient was more rapid than the fast calcium signal. Spironolactone, an inhibitor of the intracellular aldosterone receptor, or cyproterone acetate, an inhibitor of the testosterone receptor, had no effect on the fast [Ca(2+)](i) signal or in the increase in IP(3) mass. These signals could mean that there are distinct nongenomic pathways for the action of these two steroids in skeletal muscle cells.

Toxic and trace elements in liver, kidney and meat from cattle slaughtered in Galicia (NW Spain)

The aims of this study were to determine the levels of some toxic and trace metals in cattle meat in Spain and to compare them with concentrations in cattle elsewhere and to maximum acceptable levels. Arsenic, cadmium, lead, copper and zinc concentrations in the liver, kidney and muscle (meat) from 438 calves (6-10 months old) and 56 cows (2-16 years old) slaughtered in Galicia (NW Spain) in 1996 were quantified. The arithmetic mean fresh weight concentrations in calf liver, kidney and muscle respectively were 0.043, 0.055, 0.004 mg/kg for arsenic, 0.032, 0.070, 0.001 mg/kg for cadmium, 0.053, 0.052, 0.009 mg/kg for lead, 64.6, 4.91, 0.677 mg/kg for copper and 47.7, 14.4, 47.8 mg/kg for zinc. In cows, these concentrations were 0.046, 0.068, 0.005 mg/kg (arsenic), 0.097, 0.458, 0.001 mg/kg (cadmium), 0.057, 0.066, 0.017 mg/kg (lead), 60.3, 3.67, 1.26 mg/kg (copper) and 59.8, 20.0, 52.7 mg/kg (zinc). Except for copper levels in the liver which were high, metal concentrations in cattle were generally low in Galicia and broadly similar to those in the rest of Europe, Australia and Canada. Arsenic, cadmium and lead concentrations in Galician cattle rarely exceeded acceptable maximum concentrations that have been adopted by many countries. Copper and zinc concentrations in Galician cattle did exceed acceptable maximum concentrations but the frequency with which this occurred depended upon which acceptable maximum concentration was used; regulatory values differ markedly between countries.

Biochemical, electrophoretic and immunohistochemical aspects of malate dehydrogenase in truffles (Ascomycotina)

The malate dehydrogenase (MDH; EC 1.1.1.37; L-malate-NAD(+)-oxidoreductase) activities of truffles of the genus Tuber (Tuber melanosporum Vittad., Tuber brumale Vittad., Tuber aestivum Vittad., Tuber magnatum Pico, Tuber rufum Pico) have been characterized with regard to the K(m) and V(max) values in the direct and reverse reactions. The isoelectrofocusing has revealed bands showing pI values ranging from pH 5.85 to 7.8. The MDH of T. melanosporum has been partially purified by hydroxyapatite treatment, DEAE-cellulose and Sephadex G-75 columns. With the partially purified T. melanosporum MDH activity polyclonal anti-T. melanosporum MDH antibodies have been prepared and used to localize MDH in the mycorrhizae and ascocarps of T. melanosporum. These antibodies inhibit T. melanosporum MDH activity as well as that of T. magnatum but not that of rabbit liver; this supports the specificity of the MDH antibodies used to localize MDH in truffle tissues.

Arsenic, cadmium, lead, copper and zinc in cattle from Galicia, NW Spain

Knowledge of trace and toxic metal concentrations in livestock is important for assessing the effects of pollutants on domestic animals and contaminant intakes by humans. Metal levels in cattle have been measured in various countries but not in Spain. In this study, the (wet wt.) concentrations of three toxic elements (arsenic, cadmium, lead) and two trace elements (copper, zinc) were quantified in the liver (Li), kidney (Ki), muscle (M) and blood (Bl) of calves (males and females between 6 and 10 months old) and cows (2-16 years old) from Galicia, NW Spain. For the toxic elements, geometric mean concentrations of arsenic in calves (sexes combined) and cows were 10.8 and 10.2 microg/kg (Li), 11.3 and 15.2 microg/kg (Ki), 3.75 and 4.25 microg/kg (M), 3.23 and 2.92 microg/l (Bl). The corresponding cadmium concentrations were 7.78 and 83.3 microg/kg (Li), 54.3 and 388 microg/kg (Ki), 0.839 and 0.944 microg/kg (M), 0.373 and 0.449 microg/l (Bl). Geometric mean concentrations of lead in calves and cows were similarly low and were 33.0 and 47.5 microg/kg (Li), 38.9 and 58.3 microg/kg (Ki), 6.37 and 12.5 microg/kg (M), 5.47 and 12.2 microg/l (Bl). Sex had almost no effect on the amount of toxic metal accumulated except that kidney cadmium concentrations were significantly higher in females than males. Age did influence accumulation; cadmium and lead (but not arsenic) concentrations in most tissues were significantly greater in cows than female calves. For the trace elements, geometric mean copper levels in calf and cow tissues were 49.9 and 36.6 mg/kg (Li), 4.27 and 3.63 mg/kg (Ki), 0.649 and 1.68 mg/kg (M) and 0.878 and 0.890 mg/l (Bl). The corresponding zinc concentrations were 46.3 and 52.5 mg/kg (Li), 14.2 and 20.7 mg/kg (Ki), 47.3 and 52.5 mg/kg (M) and 2.80 and 2.22 mg/l (Bl). Female calves had significantly higher levels than males of muscle zinc and blood copper and zinc. Female calves accumulated more copper but less zinc in the liver and kidneys compared with cows; this may have been associated with the chronic, low-level cadmium accumulation observed in cows. Overall, the levels of arsenic, cadmium, lead and zinc in cattle in Galicia do not constitute a risk for animal health. However, up to 20% of cattle in some regions in Galicia had levels of copper in the liver that exceeded 150 mg/kg wet wt. These animals may be at risk from copper poisoning.

Biogenesis and function of the yeast plasma-membrane H(+)-ATPase

One of the most abundant proteins in the yeast plasma membrane is the P-type H(+)-ATPase that pumps protons out of the cell, supplying the driving force for a wide array of H(+)-dependent cotransporters. The ATPase is a 100 kDa polypeptide, anchored in the lipid bilayer by 10 transmembrane alpha-helices. It is structurally and functionally related to the P-type Na(+),K(+)-, H(+),K(+)- and Ca(2+)-ATPases of animal cells and the H(+)-ATPases of plant cells, and it shares with them a characteristic reaction mechanism in which ATP is split to ADP and inorganic phosphate (P(i)) via a covalent beta-aspartyl phosphate intermediate. Cryoelectron microscopic images of the H(+)-ATPase of Neurospora crassa and the sarcoplasmic reticulum Ca(2+)-ATPase of animal cells have recently been obtained at 8 nm resolution. The membrane-embedded portion of the molecule, which presumably houses the cation translocation pathway, is seen to be connected via a narrow stalk to a large, multidomained cytoplasmic portion, known to contain the ATP-binding and phosphorylation sites. In parallel with the structural studies, efforts are being made to dissect structure/function relationships in several P-type ATPases by means of site-directed mutagenesis. This paper reviews three phenotypically distinct classes of mutant that have resulted from work on the yeast PMA1 H(+)-ATPase: (1) mutant ATPases that are poorly folded and retained in the endoplasmic reticulum; (2) mutants in which the conformational equilibrium has been shifted from the E(2) state, characterized by high affinity for vanadate, to the E(1) state, characterized by high affinity for ATP; and (3) mutants with altered coupling between ATP hydrolysis and proton pumping. Although much remains to be learned before the transport mechanism can be fully understood, these mutants serve to identify critical parts of the polypeptide that are required for protein folding, conformational change and H(+):ATP coupling.

Inhibition of L-tyrosine-induced micronuclei production by phenylthiourea in human melanoma cells

It was previously found that L-tyrosine oxidation product(s) are cytotoxic, genotoxic and increase the sister chromatid exchange (SCE) levels in human melanoma cells. In this work, the micronucleus assay has been performed on human melanotic and amelanotic melanoma cell lines (Carl-1 MEL and AMEL) in the presence of 1.0, 0.5 and 0.1 mM L-tyrosine concentrations to investigate if melanin synthesis intermediate(s) increase micronuclei production. L-Tyrosine oxidation product(s) increased the frequency of micronuclei in melanoma cells; 0.1 mM phenylthiourea (PTU), an inhibitor of L-tyrosine oxidation by tyrosinase, lowered the micronucleus production to the control levels. The culture of melanoma cells with high L-tyrosine in the culture medium resulted in a positive response to an ELISA-based apoptotic test. For comparison the effect of L-tyrosine on micronuclei production in human amelanotic melanoma cells was also investigated; the micronucleus production in the presence of 1 mM L-tyrosine in the culture medium was lower than that found with melanotic melanoma cells of the same cell line. The data suggest that melanin synthesis intermediates arising from L-tyrosine oxidation may cause micronuclei production in Carl-1 human melanoma cells; the addition of PTU in the presence of L-tyrosine decreased the frequency of micronuclei to about the control values thus the inhibition of melanogenesis may have some clinical implication in melanotic melanoma.

[Tics disease (Gilles de la Tourette syndrome): clinical characteristics of 70 patients]

BACKGROUND

Tourette's syndrome is a childhood-onset hereditary neurobehavioural disorder believed to occur without geographical restrictions. Although there have been reports of this disorder worldwide just a few are from Latin America.

AIM

To report a preliminary experience with a series of 70 patients and to review recent advances in this disorder.

PATIENTS AND METHOD

We reviewed patients seen in pediatric and adult neurological clinics in Santiago, Chile, all of whom fulfilled clinical diagnostic criteria for Tourette Syndrome.

RESULTS

Seventy patients were studied, 54 males (77.1%) and 16 females (22.8%), their mean age at first evaluation was 13.6 years (range 2-46). The mean age of onset of symptoms was 6.4 (range 2-20), the mean time of follow-up was 3 years. Fifty-eight patients showed simple motor tics (blinking, facial grimacing, shoulder shrugging), whereas dystonic tics like head jerking were seen in 38 patients, torticollis in 6 and oculogyric movements in 2. Complex motor tics like jumping, antics, trunk bending and head shaking were present in 16 subjects. Vocal tics were predominantly of the simple type: sniffing, throat clearing, blowing, and whistling. Complex vocal tics were seen in 12 patients, five cases showed palilalia, 3 echolalia and only six displayed coprolalia (8.5%). Tics were of mild to moderate severity in most patients. Obsessive-compulsive disorder was observed in 22.8% and attention deficit and hyperactivity disorder were present in 35.7%. Forty-five patients (64.2%) had a first degree relative with tics, nine patients (12.8%) had a family history of obsessive-compulsive disorder. The current evidence involving desinhibition of cortico-striatum-thalamic-cortical neuronal circuits in the pathogenesis of this disorder is analyzed.

CONCLUSION

Our report supports the recognized clinical homogeneity and genetical basis of Tourette's syndrome regardless of geographical region and ethnic origin.

[Long-term follow up of asymptomatic chagasic individuals with intraventricular conduction disturbances, correlating with non-chagasic patients]

This prospective study was designed to evaluate intraventricular conduction disturbances in asymptomatic patients with Chagas' disease, and patients with primary sclerosis of the conducting system of the heart (Lev-Lenègre's disease). Eighty-four asymptomatic individuals with right- or left-bundle branch block were submitted to electrophysiological evaluation and long-term follow-up. Fifty-five had positive serologic blood tests for Chagas' disease and 29 had Lev-Lenègre's disease. Mean-age of 45 years in chagasic and 63 in non-chagasic patients (p< 0.001). There were 54 (98.2%) with right-bundle branch block in chagasic and 14 (48.3%) among non-chagasic patients (p <0.001). Sinus nodal and atrioventricular nodal functions presented no differences in either group. However, mean HV interval was greater in the NCH than in the CH group (p< 0.01). After a mean follow-up of 121 +/- 63.75 months among chagasic and 94.97 +/- 67.55 months among non-chagasic patients, total mortality was 20 (36.6%) patients in chagasic and 9 (31%) among non-chagasic patients (NS). Cardiac death was recorded in 17 (85%) individuals among chagasic and 3 (33.3%) among non-chagasic patients(p <0.05). Sudden death occurred in 10 (50%) among chagasic and was not observed in non-chagasic patients (p <0. 01).

IN CONCLUSION

1. Asymptomatic chagasic individuals with intraventricular conduction disturbances showed higher cardiac mortality, sudden or non-sudden death in relation to non-chagasic individuals. 2. The evaluated electrophysiological parameters were of no prognostic value in relation to mortality, although programmed ventricular stimulation was not performed.