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.

Growth hormone and aging

In elderly people, vascular alterations and degenerative alterations of the Central Nervous System (CNS) are two of the most common reasons for illness and death. Lipid pattern modifications and menopause in women are some of the causes for the appearance of these alterations. Vascular endothelium is in part responsible for vascular homeostasis, through the production of several vasoactive factors. Growth hormone (GH) exerts effects on the CNS and on the vascular endothelium, since GH deficient subjects exhibit endothelium-dependent alterations, which recover under substitutive GH treatment. Growth hormone has important actions on lipid metabolism that also play a role on vascular and endothelial function. Moreover, cardiac function improves when GH is associated to angiotensin II receptor blockers. Elderly people exhibit a physiological GH deficiency that could affect their vascular and cerebral functions. A study was carried out using old Wistar rats to clarify the effects of GH on the vessels under chronic "in vivo" conditions. The response to various vasoactive substances in aortic rings has been evaluated. An increase in the aortic media thickness was seen in old rats, which showed also a reduction in the vasodilator response to isoprenaline as compared to young animals. GH treatment partially restored the vasodilator response and reduced media thickness. Neuronal population was reduced in the hypocampus of old rats as compared to young ones and GH treatment was able to significantly enhance the number. Neurotransmitters were measured in several cerebral areas to establish differences between young and old GH-treated or untreated animals. Glutamine, Arginine and Aspartate were reduced in old animals whereas Citruline was increased. GH treatment restored in all cases the levels corresponding to young rats.

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.

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.

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.

Lead induces endothelium- and Ca2+-independent contraction in rat aortic rings

The contractile effect of lead on rat aortic rings was examined. Lead (0.1-3.1 mM) elicited concentration-dependent but endothelium-independent contractions, which were unaffected by prazosin (1 microM). The contractile effects of lead were similar when the aortic rings were bathed either in the absence or presence of external Ca2+. Lanthanum (1 mM) but not verapamil (I pM) inhibited the lead contractions; hence non-L-calcium channels are involved in such effect. In addition, lead induced contractions on aortic rings incubated in Ca2+-free EGTA-containing solution for 70 min., an experimental condition in which intracellular Ca2+-stores are depleted. Finally, the contractile effect of lead was not modified by calphostin C (an inhibitor of protein kinase C). In conclusion, the present results suggest that in rat aorta, the lead-induced contraction is independent of extra- and intracellular calcium stores. In addition, the effect of lead is independent of either catecholamines or protein kinase C. It is likely that in rat aorta, lead enters into the smooth muscle cells through non-L-calcium channels, and when acting like calcium on the contractile machinery it produces contraction. The differences observed between our results and those obtained by other authors may indicate that the mechanism of the contractile effect of lead varies among the different blood vessels.

Ionic currents in PC12 cells differentiated into neuron-like cells by a cultured-sciatic nerve conditioned medium

The present work deals with the identification of the ionic currents found in PC12 cells differentiated into neuron-like cells by a 9-11-day cultured-sciatic nerve conditioned medium (CM). PC12 whole-cell currents were measured after chronic exposure to CM. The results obtained in these CM-treated cells reveal that the functional expression of Ca(2+) currents is increased, that Na+ currents are not affected, and that a transient K+ current and a K+ delayed rectifier (K+ dr) current are increased. The combination of nifedipine and omega-conotoxin GVIA (omega-CgTX) does not block completely the increased functional expression of the Ca(2+) current. The remaining current is blocked by omega-agatoxin TK indicating that P/Q-type channels are additionally contributing to the increase in Ca(2+) current. NGF-treated PC12 cells, used as positive controls, confirm that NGF increases the expression of voltage-dependent Na+ currents and of Ca(2+) currents. In addition, we found that NGF also increases a K+ dr-type current in these cells. The results obtained with the CM might be due to a molecule or a mixture of molecules released into the medium by the 9-11-day cultured sciatic nerves.

Hantavirus pulmonary syndrome due to Andes virus in Temuco, Chile: clinical experience with 16 adults

STUDY OBJECTIVES

To describe the clinical features and laboratory abnormalities of 16 adults with confirmed Hantavirus pulmonary syndrome (HPS) due to Andes virus in Temuco, Chile.

DESIGN

A retrospective chart review abstracting clinical, radiologic, laboratory, and epidemiologic data.

SETTING

ICU of the university teaching hospital in Temuco, Chile.

PATIENTS

Sixteen patients with HPS treated between 1997 and 1999.

RESULTS

Patients were aged from 19 to 45 years, 82% were men, and 88% were farm or timber workers with occupational acquisition of HPS. After an incubation period ranging from 5 to 25 days, a prodromal influenza-like phase frequently was accompanied by abdominal symptoms. From 1 to 7 days later, respiratory insufficiency and hemodynamic instability suddenly appeared. In 81%, hemorrhage was evident; in 63%, moderate-to-severe bleeding occurred. The most prominent laboratory abnormalities were hemoconcentration, leukocytosis, thrombocytopenia, altered partial thromboplastin time (PTT), creatine kinase, transaminases, and hyponatremia. Creatinine elevation was common, with clinical importance in two patients. All patients had severe hypoxemia and pulmonary edema. Fifteen patients received supportive treatment, and 5 patients were treated with corticosteroids. The mortality rate was 43.8%.

CONCLUSIONS

Bad prognostic factors appeared to be severe hypotension, lower PaO(2)/fraction of inspired oxygen values, prolonged PTT, hemorrhage, greater volume load, and profuse bronchorrhea. The effects of treatment with corticosteroids could not be determined. Hemorrhage and renal involvement were common in our patients, features not often described in the North American literature of Sin Nombre virus HPS.

Novel mechanisms in murine nitrofen-induced pulmonary hypoplasia: FGF-10 rescue in culture

We evaluated the role of the key pulmonary morphogenetic gene fibroblast growth factor-10 (Fgf10) in murine nitrofen-induced primary lung hypoplasia, which is evident before the time of diaphragm closure. In situ hybridization and competitive RT-PCR revealed a profound disturbance in the temporospatial pattern as well as a 10-fold decrease in mRNA expression level of Fgf10 but not of the inducible inhibitor murine Sprouty2 (mSpry2) after nitrofen treatment. Exogenous FGF-10 increased branching not only of control lungs [13% (right) and 27% (left); P < 0.01] but also of nitrofen-exposed lungs [23% (right) and 77% (left); P < 0.01]. Expression of mSpry2 increased 10-fold with FGF-10 in both nitrofen-treated and control lungs, indicating intact downstream FGF signaling mechanisms after nitrofen treatment. We conclude that nitrofen inhibits Fgf10 expression, which is essential for lung growth and branching. Exogenous FGF-10 not only stimulates FGF signaling, marked by increased mSpry2 expression, in both nitrofen-treated and control lungs but also substantially rescues nitrofen-induced lung hypoplasia in culture.

Phospholipid remodeling/generation in Giardia: the role of the Lands cycle

Recent results suggest that Giardia is able to carry out deacylation/reacylation reactions (the Lands cycle) to generate new phospholipids, effectively bypassing the de novo synthesis of the entire phospholipid molecule. The successful operation of this deacylation/reacylation cycle is important for Giardia because this protozoan parasite possesses limited lipid synthesis ability. This article discusses how Giardia might use the Lands cycle to alter phospholipids acquired from the host during its colonization in the human small intestine.

[Effects of proteolytic enzymes and sexual abstinence on alpha glucosidase biochemical quantification in human seminal plasma]

BACKGROUND

alpha-glucosidase is found in human seminal plasma as an acid form, located in accessory glands, and as a neutral form secreted almost exclusively by the epididymis. Quantification of alpha-glucosidase activity is a marker of the secretory function of the epididymis and indemnity of the sperm transport pathway.

AIM

To obtain reference values for alpha-glucosidase in normal samples of seminal plasma, to evaluate its behavior in serial samples and to determine the effect of proteolytic enzymes.

MATERIAL AND METHODS

Fifty donors, with normal semen analysis according to the criteria of the World Health Organization, were evaluated. For the study with alpha-quimotrypsin, 0.1 to 10 mg/ml of the enzyme was added to the seminal plasma from a group of donors. alpha-glucosidase was also measured in semen obtained from nine patients at different time intervals.

RESULTS

Normal alpha-glucosidase values ranged from 14.52 to 25.69 microU/ml. Concentrations up to 10 mg/ml of alpha-quimotrypsin (10 times of that usually used in the liquefaction of the semen) did not alter the quantification of alpha-glucosidase. Serial determinations revealed oscillations in their magnitude, which stayed in each patient's characteristic range. However a subgroup presented a marked reduction of the activity of alpha-glucosidase as the abstinence diminished (40%).

CONCLUSIONS

Evaluation of alpha-glucosidase in seminal plasma gives reliable information of the secretor state of the epididymis and especially replaces invasive methods used to evaluate the indemnity of the spermatic transport from the epididymis to the anterior urethra.

Analytical methodology for the detection of benzodiazepine consumption in opioid-dependent subjects

Benzodiazepines are frequently abused by heroin users, but not all compounds have shown the same abuse liability. We developed an analytical method that was able to detect various benzodiazepine compounds in a single run. Enzymatically hydrolyzed urine underwent a liquid-liquid extraction procedure with chloroform/isopropanol (9:1) at pH 8-9 followed by a solid-liquid clean-up (Bond Elut TCA C18) to obtain appropriate extracts for HPLC analysis. Mobile phase composition was optimized by means of the linear solvation energy relationship methodology based on Reichardt's normalized solvatochromic parameter (E(T)N). The method was validated for the simultaneous detection and quantitation of alprazolam, alpha-hydroxyalprazolam, oxazepam, 7-aminoflunitrazepam, flunitrazepam, nordiazepam, lorazepam, and diazepam. The prevalence of benzodiazepine consumption in 229 opioid-dependent subjects on methadone-maintenance treatment was 48%. Oxazepam and nordiazepam were the benzodiazepines most frequently recoved in urine samples. The prevalence of alprazolam use (40%) was higher than that of flunitrazepam (10%).

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.

[Prevalence of anti-hantavirus antibodies in health care personnel in direct contact with patients with hantavirus pulmonary syndrome in Temuco, Chile 1997 to 1999]

BACKGROUND

An outbreak of Hantavirus Cardiopulmonary Syndrome (HVCS) caused by the Andes virus, affected Chile since 1995. Antibodies to Hantavirus in health care workers who had cared patients with HVCS in Coybaique, Argentinean reports and familial clustering of bantaviral illness, raised the possibility of person to person transmission. Familial clustering could occur secondary to a similar exposure to a common infected environment of more than one member of the family. Moreover, the prevalence of antibodies in health care workers in Coyhaique does not differ from the prevalence in general population in that region.

AIM

To study the prevalence of antibodies to Hantavirus in health care workers exposed to body fluids of 20 patients.

MATERIAL AND METHODS

Among health care workers exposed to patients with HVCS, we registered information about the exposure to patients and to the environment outside the hospital in which they could have been infected. IgG antibodies against Hantavirus were measured by ELISA using two dilutions.

RESULTS

Sixty seven workers were studied. Of these, 73% were exposed to respiratory secretions and blood, 21% to blood and 6% to respiratory secretions. Only 6% protected themselves properly, 49% used facial masks and gloves, 25% only facial masks, 7% only gloves and 12% used no protection measures. In none of these workers, Hantavirus antibodies were detected.

CONCLUSIONS

These results are supporting evidence against person to person transmission of the Andes virus.

[Risk factors for home deaths due to pneumonia among low socioeconomic level Chilean children, Santiago de Chile (1994)]

BACKGROUND

Pneumonia is the main cause of late infant mortality in Chile. Over 60% of these deaths occur at home. The lack of hospital beds and the inadequate outpatient management are contributing factors.

AIM

To assess risk factors for home deaths due to pneumonia in Chilean children.

PATIENTS AND METHODS

The clinical and environmental histories of 53 (39 male) children that died due to pneumonia in their homes were analyzed. The cause of death was confirmed by necropsy with histopathological studies in all cases. These cases were compared with 88 control children of similar age, gender, socioeconomic status and living in the same geographical area of Metropolitan Santiago.

RESULTS

Fifty four percent of deceased children were of less than 3 months of age and only 3 cases and their controls were above 1 year old. Identified risk factors for death were malnutrition with an odds ratio of 30.6 (CI 3.9-64.8, p < 0.001), low birth weight with an odds ratio of 5 (CI 1.8-14.1, p < 0.001), previous admissions to hospitals with an odds ratio of 5.79 (CI 2-17.1, p < 0.001), congenital malformations (mainly cardiac) with an odds ratio of 8.4 (CI 2-39.9, p = 0.001) and a history of bronchial obstruction with an odds ratio of 5.68 (p < 0.001). Identified maternal risk factors were smoking with an odds ratio of 4.13 (CI 1.6-10.7 p < 0.001) and being a teenager with an odds ratio of 4.3 (CI 1.7-11, p < 0.001). Malnutrition, low birth weight, history of previous hospital admissions and having a teenager or smoker mother were considered as independent risk factors using a stepwise analysis.

CONCLUSIONS

Chilean low income children have identifiable risk factors for death at their homes due to pneumonia, that can be preventively managed.