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Biomedical subjects

M López Alonso

Publications and source records attributed to M López Alonso.

17 recordsLinked to original sources
PubMed2005

Plasma malonaldehyde (MDA) and total antioxidant status (TAS) during lactation in dairy cows.

Metabolic profiles are widely used to monitor health, reproductive status and nutritional status. In the last few years, the evaluation of oxidative stress has contributed increasingly to our knowledge of the fundamental mechanisms involved in metabolic disorders, especially important in dairy cows, in which lactation imposes great physiological demands on the body's homeostatic mechanisms. The aim of the present study was to evaluate oxidative status in healthy cows during lactation (from lactation onset to peak lactation) using two parameters: (i) plasma levels of malondialdehyde (MDA) and (ii) total antioxidant status (TAS). Our results confirm that nutrition can influence the characteristic metabolic changes occurring between lactation onset and peak lactation. In addition, the combination of MDA and TAS can provide complementary information about the metabolic status of the cow. Thus, the proper metabolic adaptation to the onset of lactation, showed by metabolic profiles, contrasts with the high levels of free radicals which cause lipid peroxidation and high MDA values (68.99+/-33.64 microm/L) which is maintained only for a short period of time. In this moment, the antioxidant system can cope efficiently with lipoperoxide production. The most remarkable fact was the great inter-individual variations observed in MDA that might be studied in further investigations. When the animal reaches peak lactation, metabolic status is stabilized, and this is reflected by antioxidant status with mean values of 28.87+/-5.33 microm/L for MDA and 0.154+/-0.002 mmol/L for TAS values.

Animals↗
PubMed2005

[Reliability index of anorectal manometry for the diagnosis of Hirschspurng disease].

UNLABELLED: The anorectal manometry (AM) and suction rectal biopsy (BS) are the main and accepted methods for diagnosis of Hirschsprung disease (HD). The reliability of these methods in newborns have been subject of controversy up to the present. MATERIAL AND METHODS: For diagnosis of HD purpose we have performed 2227 AM records in 1744 children. Initially we used a minichamber type probe joined to a close system to perform AM. From 1984 we developed a new type of 4 ways miniprobe connected to an open system which improved the reliability of the records. RESULTS: The indexes of reliability for our database have been the following: sensitivity 98%, specificity 97%, positive predictive value 85%, negative predictive value 99%, false positive 3.4% and false negative 1.8%. CONCLUSIONS: AM is a non invasive method with a high reliability, available in our hospital. It is a choice method for diagnosis of HD.

Anal Canal↗
PubMed2005

[Acid and non-acid gastro-esophageal reflux in newborns. Preliminar results using intraluminal impedance].

Preterm infants present often Gastroesophageal refluxes (GER). Esophageal pH monitoring to reflux detection is of limited use in this infants because their gastric pH is normally higher than 4 for 90% of the time. Other methods such as the Intraluminal Impedance Technique (MII) technique and the use of micromanometric catheters try to palliate the difficulties for measuring GER by pH monitoring. The aim of this study, in a first step, was to obtain the normal Intraluminal Impedance values on control children and, in a second step, to study the relationship between GER and cardiorespiratory episodes using simultaneous recording of the end-tidal fraction of expired CO2, 02 saturation by pulse-oximetry, respiratory frequency, esophageal impedance and manometry, gastro-esophageal pHmetry, and electrocardiography in selected patients. Data from simultaneous pH and Intraluminal Impedance during 24 hours in 7 control preterms showed 89 acid refluxes, 192 non-acid refluxes, 79.36% of all refluxes reached the proximal esophagus. Therefore the impedance is an innocuous method which opens new horizons in the study of such a common illness as the GER in the preterm infants.

Body Composition↗
PubMed2003

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.

Age Factors↗
PubMed2003

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.

Air Pollutants↗
PubMed2003

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.

Animal Feed↗
PubMed2002

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.

Animals↗
PubMed2002

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.

Abattoirs↗
PubMed2002

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.

Animals↗
PubMed2000

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.

Abattoirs↗
PubMed2000

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.

Animals↗
PubMed2000

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.

Animals↗
PubMed1999

Morphology and amplitude values of the P and T waves in the electrocardiograms of Spanish-bred horses of different ages.

This investigation was undertaken to determine values of electrocardiographic parameters in Spanish-bred horses at different stages of growth. The study was carried out on 179 healthy Spanish-bred (Andalusian) horses (98 females and 81 males), which were aged between 1 month and 17 years. The ECGs showed P waves of different configurations. The bifid shape deflection of the P wave was generally more frequent than the simple one in animals from 6 months of age. The first component of bifid P waves (P1) did not vary in a statistically significant way with increasing age, showing a mean value of 0.105 mV. The amplitudes of the P2 (the second component of the bifid P waves) and simple P waves showed statistically significant differences between the age groups. The highest values were found in animals up to 3 months and over 2 years of age. Several configurations of the T wave were observed in the different age groups: a negative shape was generally present for the youngest animals (foals up to 2 years old); the biphasic (/+) pattern became more frequent in animals 3 and 4 years old. In adult horses the positive configuration was the most frequent. No statistically significant differences according to age were found for the amplitude values of the different T-wave configurations.

Aging↗
PubMed1998

The influence of reproductive stage on the selenium status of sheep in a low-selenium region.

The selenium status of sheep was evaluated during the reproductive stage in a region of low selenium level. Serum selenium concentration, whole blood glutathione peroxidase activity (GSH-Px), which is a good indicator of protection against oxidative damage, as well as the activities of creatine kinase (CK) and aspartate aminotransferase (AST), the plasma indicators of muscle damage, were evaluated in a group of ewes during gestation and lactation and in their lambs. The selenium requirements of ewes were found to increase during lactation. There were no differences in GSH-Px activity between the experimental and the control groups throughout the reproductive stage. In the second half of pregnancy GSH-Px activity was subnormal. In spite of this, no evidence of existing pathologic conditions associated with selenium deficiency was found, since the muscle markers CK and AST were within the normal range. In the same way, no distinct symptoms of nutritional myopathy were observed in the lambs, suggesting that the low selenium level found in the ewes did not cause alterations in their development.

Animals↗
PubMed1992

[Manometric study in the newborn].

Hirschsprung's disease in the newborn period has a bad prognosis due to the high mortality rate caused mainly by enterocolitis. It has been shown that the incidence of enterocolitis diminishes with the precocity with which diagnosis is made. All diagnostic methods have problems in the neonate. We intent to investigate the anorrectal manometry in the neonate using a probe devised and built by us. The hypothesis we try to prove is that the rectoanal reflex is present in all newborn, having no relation with age, length of gestation period, nor weight. The characteristics of the probes used allowed long recording sessions without any sedation of patients. The validity of this technique is unquestionable from the view of the reliability of the recordings independently of the weight, gestational age and birth age of the infants.

Female↗
PubMed1986

[Ovarian torsion in early childhood].

Three cases of torsion of normal the uterine adnexa in premenarcheal girls are reported. The possible etiopathogenic mechanisms are commented, and the operative management is discussed. The value of ultrasonography in early diagnosis is pointed out.

Abdomen, Acute↗