Biomedical subjects

C Domínguez

Publications and source records attributed to C Domínguez.

At least 19 recordsLinked to original sources

PubMed2005

Effect of plane of nutrition on seasonality of reproduction in Spanish Payoya goats.

The aim of this study was to determine if there is a seasonal pattern of sexual activity in female Payoya goats and if this seasonality could be modulated by nutrition. During the experimental period of 20 months, 43 non-pregnant adults goats were penned under natural photoperiod at latitude 37 degrees 15'N. At the onset of the experiment, the animals were allocated to three experimental groups differing in the level of nutrition and whether the animals were entire or ovariectomized does. The high nutrition group (H, n = 16 entire does) receiving 1.5 times maintenance requirements. The low nutrition group (L, n = 16 entire does) and an ovariectomized and oestradiol treated group (OVX, n = 11 ovariectomized does) received a diet supporting their maintenance requirements. The groups were balanced for live weight (LW) and body condition score (BCS) at the beginning of the study. In entire goats, oestrus was tested daily using aproned males, ovulation rate was assessed by laparoscopy 7 days after identification of oestrus and plasma samples were obtained twice per week for progesterone assay. OVX goats were isolated from the other groups and bucks, plasma samples were assayed twice per week for LH and there were four intensive sampling periods during the year to determine LH pulsatility. LW and BCS were recorded for all animals once a week. A clear circannual cycle in live weight change was observed in all experimental groups, being relatively stable or slightly decreasing in summer and autumn and increasing during winter and spring. The effect of exposure to high (H) rather than low (L) nutrition was to cause earlier onset of ovarian activity (5 versus 17 August; P < 0.05), and expression of oestrous (16 August versus 2 September; P < 0.01) and later cessation of reproductive activity (ovulation 11 February versus 17 January; P < 0.01). Consequently, seasonal anoestrus was 32 days shorter in does on the higher plane of nutrition (P < 0.01). The seasonality of reproductive activity was confirmed in the OVX does, with reduced LH concentrations during spring and summer, and increased LH concentrations in autumn and winter. There was no effect of nutrition on ovulation rate. These results demonstrate that the female Payoya goat exhibits marked reproductive seasonality which is modulated by nutrition but possibly not ovulation rate.

Animals↗

PubMed2004

[Reduction of periodontoid masses following posterior arthrodesis: review of two new cases not linked to rheumatoid arthritis].

Inflamatory periodontoid pannus is quite common in patients with rheumatoid arthritis. However, the occurrence of a pannus-like periodontoid mass that is unassociated with rheumatic inflammation is less frequent. Transoral surgery associated with a posterior stabilization has long been considered one of the most efficient methods to resolve the problem of instability in patients presenting neurological deficits secondary to the pannus. We present two cases of non rheumatic etiology, in which an occipito-cervical arthrodesis was used to resolve the proliferative lesion around the odontoid apophysis. Two women (67 and 60 years old respectively) presented symptoms of pain and neurological deterioration with an antecedent of possible past odontoid fracture in one case, and a previous large anterior cervical arthrodesis to correct spondylarthrosis in the other case. Both patient's neurological condition improved after placement of an arthrodesis through a posterior approach.

Aged↗

PubMed2002

Prevalence of Salmonella and Campylobacter in retail chicken meat in Spain.

From February to November 1999, 198 samples of chicken meat for sale in retail outlets and supermarkets in nine provinces of Castilla and León (Spain) were analysed for the prevalence of Salmonella and Campylobacter. Salmonella was isolated from 71 (35.83%) of the samples analysed. The predominant serovars were S. enteritidis (47.88%), S. hadar (25.35%) and serotype 4,12:b:-(II) (19.71%). Other serovars such as S. mbandaka, S. derby, S. virchow and S. paratyphi B were isolated in much lower levels. Thermophilic campylobacters were isolated in 49.50% of the samples studied.

Animals↗

PubMed2001

Automated solid-phase extraction for sample preparation followed by high-performance liquid chromatography with diode array and mass spectrometric detection for the analysis of resveratrol derivatives in wine.

A method has been developed for the simultaneous determination of resveratrol in all its forms (free isomers and glycosylates) in wines by high-performance liquid chromatography with diode array and mass spectrometric detection. Prior to injection into the column, preconcentration of the sample by automated solid-phase extraction is carried out. In the detection by UV absorption, quantitation was carried out at 280 and 305 nm, and in detection by mass spectrometry, quantitation was performed in the selected ion monitoring mode at m/z 228 and at m/z 238. A comparative study between both detection systems was carried out.

Automation↗

PubMed2001

Late-onset metachromatic leukodystrophy clinically presenting as isolated peripheral neuropathy: compound heterozygosity for the IVS2+1G-->A mutation and a newly identified missense mutation (Thr408Ile) in a Spanish family.

We report the case of a 50-year-old woman and her 32-year-old daughter, both of whom are affected with adult-onset metachromatic leukodystrophy (MLD) clinically presenting as peripheral neuropathy. Arylsulfatase A (ARSA) activities were markedly reduced, and electrophysiology showed a severe demyelinating neuropathy with features of chronic acquired demyelinating polyneuropathy. Molecular genetic studies of the family revealed that the proband and her affected daughter are compound heterozygotes for the common IVS2+ 1G-->A mutation and a newly identified missense mutation, Thr408Ile. This case indicates that adult metachromatic leukodystrophy should be considered in adult patients with demyelinating peripheral neuropathy of unknown etiology.

Alleles↗

PubMed2000

4-Alkylidenyl glutamic acids, potent and selective GluR5 agonists.

Twenty-four 4-alkylidene glutamic acids were synthesised and tested as potential subtype selective GluR5 and 6 ligands. It was found that a critical size of alkylidene group gave potent and selective GluR5 receptor agonists. LY339624 had Kis of 0.0326 and >100 microM on GluR5 and 6 receptors, respectively.

Animals↗

PubMed2000

4-Alkyl- and 4-cinnamylglutamic acid analogues are potent GluR5 kainate receptor agonists.

Enantiomerically pure (2S,4R)-4-substituted glutamic acids were prepared and tested for homomeric GluR5 and GluR6 kainate subtype receptor affinity. Some of the 4-cinnamyl analogues showed high selectivity and potency (K(i) < 25 nM) for the GluR5 receptors. The greatest selectivity and potency were achieved with the 3-(2-naphthyl)prop-2-enyl compound. This compound, LY339434, has negligible activity at the AMPA and kainate receptors GluR1, -2, -4 and -6. Although, LY339434 shows agonist activity at NMDA receptors in cultural hippocampal neurons (approximate EC(50) of 2.5 microM), we consider that LY339434 should be a useful pharmacological tool for the investigation of the functional role of GluR5 kainate receptors.

Acetylene↗

PubMed2000

Characterization of antiresonant reflecting optical waveguide devices by scanning near-field optical microscopy.

Silicon-based antiresonant reflecting optical waveguide (ARROW) devices were studied by means of a scanning near-field optical microscope. Various structures such as a Y junction of a Mach-Zehnder interferometer and a directional optical coupler were characterized, showing the propagation of the light inside the devices simultaneously with the topography. Scattering on the splitting point of the Y junction was shown, as well as a partial coupling of the light between the two branches of the coupler. Measurements on the decay length of the evanescent field were also performed to study the use of the ARROW waveguide for sensor purposes.

Journal Article↗

PubMed1999

Qualitative and quantitative analysis of new alkyl amide arginine surfactants by high-performance liquid chromatography and capillary electrophoresis.

A protocol for the qualitative and quantitative analysis of novel arginine-based cationic surfactants using HPLC and CE was studied and compared. The optimization of the analytical conditions was carried out through a systematic variation of the experimental parameters such as mobile phase, eluent conditions, ion pairing and amount of sample for HPLC, and type of buffer, ion strength, type and amount of organic solvent, sample injection time, applied voltage and column washing and conditioning for CE.

Amides↗

PubMed1999

Adult glycogenosis II with paracrystalline mitochondrial inclusions and Hirano bodies in skeletal muscle.

Hirano bodies constitute eosinophilic intracytoplasmic inclusions, typically seen in the central nervous system, where they are related to senility and certain dementias such as Alzheimer's disease or the Parkinson-dementia complex. They have been found in different tissues of experimental animals and, on rare occasions, in extraocular muscles of elderly individuals. However, to our knowledge they have not been described in skeletal muscle in locations other than extraocular muscles or associated with muscle pathology. Glycogenosis II or Pompe's disease, is a metabolic disorder caused by acid maltase deficiency and is characterized by glycogen accumulation in lysosomes in various tissues, including skeletal muscle. There are three clinical forms depending on age at onset, the most frequent being the childhood form. We present the histopathological and ultrastructural findings of a muscle biopsy performed in a case of the adult form of glycogenosis II which showed, in addition to characteristic lysosomal glycogen storage, paracrystalline mitochondrial inclusions and, as an exceptional finding, intracytoplasmic Hirano bodies in some muscle fibres.

Female↗

PubMed1999

Lipoid proteinosis. A biochemical and ultrastructural investigation of two new cases.

Lipoid proteinosis is a rare autosomal recessive disease characterized by cutaneous and visceral lesions, in which large amounts of amorphous material are constantly found in stroma. Morphological and biochemical studies indicate abnormal collagen production, but little attention has been paid to the lipid component of lesions. Microscopic and ultrastructural studies of skin, with special emphasis on fibroblasts, vessels, nerve endings and eccrine sweat glands, were conducted in two patients with lipoid proteinosis. Biochemical studies were undertaken in cultured fibroblasts. Evidence of lysosomal storage in epithelial cells of eccrine sweat glands and in dermal histiocytes, very similar to that found in some metabolic disorders, particularly Farber disease, was found in both cases. Our findings suggest that two alterations might coexist in lipoid proteinosis, one characterized by impaired normal collagen production and the other related to a metabolic defect which may lead to accumulation of ceramide or more complex lipids.

Adult↗

PubMed1999

[Single-system ectopic ureters. A review of 19 cases].

Single system ectopic ureters are usually associated with multiple congenital abnormalities and the corresponding renal units is frequently abnormal. 19 cases of single system ectopic ureters were diagnosed and treated in our hospital during the last 20 years. The patients were less than 11 years old. The abnormality was bilateral in two cases and the 63% of all had associated malformations, being the anorectal abnormalities the most frequent. The incidence of reflux into the ectopic ureter was 57%, and the association to unilateral or contralateral renal agenesis, 26.3%. Thirteen ectopic ureters were reimplanted successfully into the bladder, and the cases of nonfunctioning kidneys were removed (nephroureterectomy). The follow-up period was 10 months to 14 years, developing the 68% of the cases without any complication and a good renal function. Two patients were transplanted due to a kidney failure. Diagnosis is often extremely difficult and requires a high degree of suspicion. This diagnosis may be incidental, and it may be made during investigation of patients with other malformations. An early diagnosis and treatment must be made in order to avoid a disturbance of renal function. We wish to point up the high incidence of reflux into the ectopic ureter and the high association to renal agenesis in the single system ectopic ureters in comparison with ectopic ureter of duplex system.

Abnormalities, Multiple↗

PubMed1998

Study of cytotoxicity mechanisms of silver nitrate in human dermal fibroblasts.

Certain concentrations of the antiseptic AgNO3, a potent broad-spectrum antimicrobial agent, exert cytotoxic effects on fibroblasts and endothelial cells which are directly related to the wound-healing process. In vitro assessment of human fibroblast cytotoxicity has proved to be a useful method for characterizing cell toxicity mechanisms of topically-applied antiseptics. In the present study human dermal fibroblasts were exposed to AgNO3 at concentrations of 4.12-82.4 microM for 8 and 24 h. Silver ions greatly inhibited fibroblast proliferation and prolonged AgNO3 exposure produced Ag-dependent cell loss. In the sequence of events occurring during our in vitro experimental model, the inhibitory action on DNA synthesis was the primary event in AgNO3 cytotoxicity, associated with significant loss of cell protein. Both parameters decreased as the content of fetal calf serum (FCS) in the exposure medium was gradually reduced from 10 to 2%. The parallel study of DNA synthesis and cell protein content suggests that the toxic damage produced by silver in different phases of the cell cycle may lead to destruction of the entire cell population and therefore hinder the tissue regeneration process. A concentration- and time-dependent depletion of intracellular ATP content is also caused by ionic silver, thereby compromising the cell energy charge which precedes human dermal fibroblast death. Concomitant incorporation of FCS to the medium always attenuated Ag+ cytotoxicity curves in a concentration-dependent fashion and maximum protection was observed at 10% in situations closely resembling physiological conditions.

Adenosine Triphosphate↗

PubMed1998

Impact of oxygen therapy on antioxidant status in newborns. Relationship with infection risk.

Newborns requiring intensive clinical care are susceptible to a wide range of excessive oxygen free radical production-related problems. In utero, fetal organs, particularly lungs, are exposed to relatively hypoxic tensions which rise abruptly after birth and this transition may cause oxidative injury in the neonate. The aims of this study were to determine oxygen free radical activity in neonates at the first 24 h, examine the role of immaturity and infection risk and compare the degree of oxidant stress in newborns treated with different oxygen concentrations. Plasma selenium levels in neonates with high infection risk (IR) were significantly lower than in healthy neonates. Comparative study of selenium in preterm, term and young infants showed age-related increases and differences were significant. Plasma selenium values were lower when oxygen therapy was administered. Vitamin E levels were significantly decreased in IR compared with healthy newborns. The results suggest that selenium and vitamin E deficiencies predispose to neonatal infection and that supplementary oxygen contributes significantly to decreasing the antioxidant defence system.

Antioxidants↗

PubMed1998

Enhanced oxidative damage in cystic fibrosis patients.

Antioxidant depletion and increased free radical production by inflammatory cells have been described in cystic fibrosis (CF) patients. To evaluate oxidative damage intensity, we measured plasma concentrations of malondialdehyde, hydroperoxides and protein carbon groups as markers of oxidative injury to lipids and proteins in a group of 101 CF patients free of acute exacerbation, and in 43-112 controls. Moreover, we estimated antioxidant function by measuring activities of erythrocyte superoxide dismutase, glutathione reductase and vitamin E concentrations. In CF patients, malondialdehyde and hydroperoxide plasma levels were significantly higher than in controls (p < 0.001). Increased lipid peroxidation was documented by these two markers. Parallel rises in protein carbonyls in plasma of CF patients were observed (p < 0.0001). These patients presented biochemical but not clinical vitamin E deficiency. Glutathione reductase and superoxide dismutase activities were significantly higher than in controls. These results show a serious imbalance of CF patients between oxidant-antioxidant status leading to oxidative stress.

Adolescent↗

PubMed1998

Oxidant-antioxidant imbalance in blood of children with juvenile rheumatoid arthritis.

Juvenile rheumatoid arthritis (JRA) is the most commonly diagnosed rheumatic disease in children and may represent not a single disease, but rather a syndrome of diverse aetiologies in which inflammation is an exceedingly complex process. Oxidative free radical production at inflammation sites contributes to tissue damage and could also play a significant role in the pathogenesis of JRA. The aim of this study was to evaluate the antioxidant status and lipid peroxidation parameters related to the clinical form of JRA. Plasma malondialdehyde and hydroperoxide concentrations in children with polyarticular and systemic JRA subtypes were significantly higher than in controls. Plasma vitamin E and beta-carotene levels of the JRA children were lower in the three forms compared with healthy children. Patients with JRA present an imbalance in the oxidant-antioxidant system that manifests clearly in the polyarticular and systemic forms through an increase in lipoperoxidation products and significant decrease in the lipid-soluble antioxidants vitamin E and beta-carotene.

Antioxidants↗

PubMed1998

Lead exposure in children: levels in blood, prevalence of intoxication and related factors.

Lead is a highly toxic metal, the main source of which is contamination from combustion of unleaded petrol. The aims of this work were to detect the degree of lead exposure in a large sample of children; determine the relationship between blood lead levels (BPb) and age, sex, habitat and season of the year; and correlate BPb with zinc protoporphyrin (ZPP) values. A cross-sectional study was carried out. Blood from routine extractions drawn at our centre was used. BPb and ZPP were measured by atomic absorption spectrophotometry and haematofluorimetry, respectively. We analysed 1158 blood samples from children. BPb (mean +/- SEM): 0.22 +/- 0.04 mumol l-1. Correlation BPb-age: BPb = 0.19 + 0.086 x age (months), r = 0.129, P < 0.0001. BPb was greater in boys (0.23 +/- 0.007 versus 0.20 +/- 0.006 mumol l-1, P < 0.0002). No differences were observed between habitats (urban versus rural). BPb were higher in the warm months (0.24 +/- 0.013 versus 0.21 +/- 0.007 mumol l-1, P < 0.0001). Prevalence of lead intoxication (BPb > 0.48 mumol l-1) was 4.2%. No differences in prevalence were found among the different groups. The correlation between BPb and ZPP showed r = 0.0969, P = 0.0024. Utility for screening: sensitivity of 53.7% and specificity of 59.3% (cut-off point of 60 mumol ZPP mol-1 haem). We can conclude that lead exposure in children in our sample was in the range reported in similar studies in other areas and countries, and below the toxic limit. None of the factors analysed significantly influenced lead intoxication prevalence. There was no good correlation between ZPP and BPb in our samples and the ZPP cut-off point used did not present good specificity and sensitivity values.

Age Factors↗

PubMed1998

Anaphylactic reaction to ingestion of Quercus ilex acorn nut.

BACKGROUND: A patient experienced an anaphylactic reaction after eating acorn nuts, fruit of the holm oak (Quercus ilex), one of the most abundant trees in Spain. Several urticaria episodes upon ingestion of peanuts were also referred. OBJECTIVE: To assess the hypersensitivity reaction to acorn and to characterize the allergenic proteins involved. METHODS: Cutaneous tests were performed using the skin-prick technique, using a large variety of grass, tree and weed pollens as well as fresh nuts and nut extracts. Specific IgE determination was assessed by RAST. IgE binding bands were determined by SDS-PAGE immunoblotting. RESULTS: Skin-prick tests were strongly positive with acorn and peanut. Olea europaea, Quercus alba, Quercus ilex and grass pollens also elicited a weal higher than negative control. Patient serum had measurable levels of IgE antibodies especially to acorn, peanut and grass pollens. Only one protein band, of 17.9 kDa molecular mass, showed IgE-binding properties in the acorn extract. The possible homology of this strong allergenic protein with the group 1 tree pollen allergens was evidenced by the partial inhibition of the western blot with Bet v 1. CONCLUSIONS: We present a case of anaphylaxis to acorn ingestion as demonstrated by in vivo and in vitro results. A 17.9 kDa IgE-binding band, showing some homology to group 1 pollen tree allergens, was recognized by patient serum.

Anaphylaxis↗