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M Alcaraz

Publications and source records attributed to M Alcaraz.

At least 19 recordsLinked to original sources
PubMed2006

Radioprotective-antimutagenic effects of rosemary phenolics against chromosomal damage induced in human lymphocytes by gamma-rays.

The radioprotective effects of carnosic acid (CA), carnosol (COL), and rosmarinic acid (RO) against chromosomal damage induced by gamma-rays, compared with those of L-ascorbic acid (AA) and the S-containing compound dimethyl sulfoxide (DMSO), were determined by use of the micronucleus test for antimutagenic activity, evaluating the reduction in the frequency of micronuclei (MN) in cytokinesis-blocked cells of human lymphocytes before and after gamma-ray irradiation. With treatment before gamma-irradiation, the most effective compounds were, in order, CA > RO > or = COL > AA > DMSO. The radioprotective effects (antimutagenic) with treatment after gamma-irradiation were lower, and the most effective compounds were CA and COL. RO and AA presented small radioprotective activity, and the sulfur-containing compound DMSO lacked gamma-ray radioprotection capacity. Therefore, CA and COL are the only compounds that showed a significant antimutagenic activity both before and after gamma-irradiation treatments. These results are closely related to those reported by other authors on the antioxidant activity of the same compounds, and the degree of effectiveness depends on their structure. Furthermore, the results for treatments before and after gamma-ray irradiation suggest the existence of different radioprotective mechanisms in each case.

Abietanes↗
PubMed2006

Dose reduction of intraoral dental radiography in Spain.

OBJECTIVES: To assess the influence of new European Union (EU) legislation on radiation doses in intraoral dental radiography in Spain. METHODS: A total of 10 109 official reports from Spanish dental offices covering the period 1996-2003 were analysed. RESULTS: The results point to a dose reduction of 19% in 7 years, with a mean dose of 3.11 mGy being administered in 2003. The third quartile value in 2002 was 4.8 mGy. Taking the EU recommended dose of 4 mGy as standard, 73.3% (2002) and 77.3% (2003) of installations are in compliance with the EU recommendations in Spain. However, there has been no further reduction in the last 3 years. The results showed that Ultraspeed dental X-ray film was used by 77.6% of the dentists in 1996-1997 and 82.3 in 2003. There was infrequent use of E-speed films (0.6%) and F-speed films (9.6%) in 2003. Statistical analysis pointed to significant differences between the doses administered and the type of processing used, the lowest exposures being measured in digital systems, which used significantly lower doses than both manual and automatic development, and when conventional radiographic films were used. CONCLUSION: The introduction of new legislation has resulted in a gradual reduction in the dose administered in intraoral dental radiology in Spain.

Analysis of Variance↗
PubMed2005

The effect of the flavonoid diosmin, grape seed extract and red wine on the pulmonary metastatic B16F10 melanoma.

OBJECTIVE: To study the effect of different phenolic compounds and red wine on pulmonary metastatic melanoma. METHODS: Swiss mice were inoculated with 500000 melanocytes B16F10 and given oral doses of diosmin, grape seed extract (GSE) and red wine. A macroscopic count was made of the metastatic nodules on the lung surface and a microscopic study by image analysis of five sections, calculating the implantation percentage and tumoral growth and invasion indices. RESULTS: Macroscopically, the group treated with diosmin showed the greatest reduction (52%) in the number of metastatic nodules compared with the control group, which was treated with ethanol, while GSE and red wine caused decreases of 26.07 and 28.81%, respectively. Microscopically, there was a decrease in the implantation percentage after the administration of diosmin (79.4%) and red wine (20.19%), and an increase of 2.12% after the administration of GSE, all relative to the ethanol-treated control. As regards the growth index, diosmin produced a reduction of 67.44% and red wine a reduction of 20.62%, while GSE again produced an increase (25.33%). The reductions in the invasion index were 45.23, 31.65 and 17.57% with diosmin, GSE and red wine, respectively. CONCLUSIONS: Diosmin originated the greatest reduction in pulmonary metastases, both at the macroscopic and microscopic levels.

Administration, Oral↗
PubMed2004

Effects of small-scale turbulence on bacteria: a matter of size.

We examined the influence of small-scale turbulence and its associated shear on bacterioplankton abundance and cell size. We incubated natural microbial assemblages and bacteria-only fractions and subjected them to treatments with turbulence and additions of mineral nutrients and/or organic carbon. Bacterial abundance was not affected directly by turbulence in bacteria-only incubations. In natural microbial assemblage incubations, bacterial concentrations were higher under turbulence than in still-water controls when nutrients were added. In general, in the turbulence treatments bacteria increased significantly in size, mainly due to elongation of cells. The addition of inorganic nutrients had a negative effect on bacterial size, but a significantly positive effect on abundance independently of other factors such as turbulence and the presence of predators. Flagellate grazing did not trigger an increase in bacterial size as a grazing resistance response in unmixed containers. With the addition of organic carbon, bacteria elongated and partly settled to the bottom of the containers, in both the turbulent and still treatment, but bacterial abundance did not further increase. Furthermore, bacteria aggregated in the turbulence treatments after the second day of incubation even in the absence of other components of the microbial community. We found that turbulence and the associated shear increase bacterial size and change bacterial morphology, at least under certain nutrient conditions. This might be due to a physiological response (enhanced growth rate and/or unbalanced growth) or due to the selection of opportunistic strains when organic carbon is in excess compared to mineral nutrients. We suggest that shear associated with turbulent flow enhances the DOM flux to bacteria directly as well as indirectly through enhanced grazing activity and photosynthetic release. The formation of bacterial aggregates and filaments under turbulence might give selective advantage to bacteria in terms of nutrient uptake and grazing resistance.

Bacteria↗
PubMed2004

The status of Spain's dental practices following the European Union directive concerning radiological installations.

OBJECTIVES: To assess the influence of new European Union (EU) legislation on dental radiology practices and the reduction in patient radiation exposure. STUDY DESIGN: A total of 7176 official reports from Spanish dental offices or clinics covering the period 1996 to 2001 were analyzed. RESULTS: Of the dental radiological installations inspected in 2001, 72.79% used the kilovoltage recommended by the EU (70 kVp) and 98.85% used at least 1.5 mm Al filtration. At least 90.11% of the installations had a focal film distance of 20 cm although there were no cases with a rectangular collimator as adapted to the size of film. Thirty percent of the installations showed a mechanical fault every year. In 17.62% of cases the radiological film was stored in the exposure room. Few clinics (10.24%) used high-speed films and only 11.95% of clinics employed digital systems. The mean dose received by patients fell during the 5 years studied by 18.75%. Radiological equipment fulfilling the EU specifications emitted significantly lower doses than other nonapproved equipment. CONCLUSIONS: The introduction of legislation has resulted in a gradual improvement in dental radiology practices.

Analysis of Variance↗
PubMed2003

Effects of several polyhydroxylated flavonoids on the growth of B16F10 melanoma and Melan-a melanocyte cell lines: influence of the sequential oxidation state of the flavonoid skeleton.

The response of B16F10 melanoma and Melan-a melanocyte cell lines to treatment with five polyhydroxylated flavonoids and gallic acid, after 24 and 72 h of exposure, was determined, and the relationship between any antiproliferative effects observed and the chemical structure is discussed. After 24 h, none of the studied compounds showed significant cytotoxic activity in the B16F10 cell line, whereas compounds with an adjacent trihydroxylated substitution pattern did affect the viability of the Melan-a cell line. After 72 h of exposure, myricetin, baicalein and gallic acid significantly inhibited both B16F10 and Melan-a cell cultures, whereas luteolin and quercetin had only a moderate effect. Eriodictyol only had an effect on Melan-a cell viability, which was reduced slightly. These results suggest that the presence of a C2-C3 double bond and three adjacent hydroxyl groups in the flavonoid A- or B-rings confers greater antiproliferative activity to the flavonoid.

Animals↗
PubMed2002

Radioprotective effects in vivo of phenolics extracted from Olea europaea L. leaves against X-ray-induced chromosomal damage: comparative study versus several flavonoids and sulfur-containing compounds.

The radioprotective effects of a polyphenolic extract of Olea europaea L. leaves (OL); the flavonoids diosmin and rutin, which are widely used as pharmaceuticals; and the sulfur-containing compounds dimethylsulfoxide (DMSO) and 6-n-propyl-2-thiouracil (PTU) were determined by using the micronucleus test for anticlastogenic activity, evaluating the reduction of the frequency of micronucleated polychromatic erythrocytes (MnPCEs) in bone marrow of mouse before and after X-ray irradiation. With treatment before X-irradiation, the most effective compounds were, in order, rutin > DMSO > OL > PTU > diosmin. These results showed, for the polyphenols studied, a linear correlation (r(2) = 0.965) between anticlastogenic activity and antioxidant capacity. The magnitude of protection with treatment after X-irradiation were lower, and the most effective compounds were, in order, OL > diosmin > rutin; DMSO and PTU lacked radioprotective activity. Therefore, OL is the only substance that showed a significant anticlastogenic activity both before and after X-ray irradiation treatments. Structurally, the free oxygen radicals and lipoperoxyradicals scavenging capacity and, consequently, the anticlastogenic activity of these polyphenolic compounds are based principally on the presence of specific functional groups, mainly catechol groups (rutin, oleuropein, hydroxytyrosol, verbascoside, luteolin), that also increase the stability of the aroxyl-polyphenol radical generated in the above processes.

Animals↗
PubMed2002

Effects of several flavonoids on the growth of B16F10 and SK-MEL-1 melanoma cell lines: relationship between structure and activity.

Although flavonoids seem to be capable of acting at all stages of the carcinogenic process, little information is available on their action in melanoma cell lines. The aim of this study was to assess the response of B16F10 and SK-MEL-1 melanoma cell lines to treatment with six different flavonoids after 24 and 72 h of exposure and to relate the response to their structure. We then compared the findings with those for melphalan treatment. When cultures were treated for 24 h, only slight inhibition at the highest concentrations (25 and 50 microM) of tangeretin and luteolin were observed, whereas melphalan caused a dose-related inhibition of growth at all concentrations. Quercetin, hesperetin, 7,3'-dimethylhesperetin and eriodictyol did not produce any effect at 24 h on B16F10 or SK-MEL-1 cells, results which point to the low toxicity of flavonoids. After 72 h of exposure culture growth was inhibited by 7,3'-dimethylhesperetin at 50 microM, but lower concentrations had no effect. Tangeretin was the most effective of the flavonoids in inhibiting B16F10 and SK-MEL-1 cell growth, showing a clear dose-response curve after 72 h. These results suggest that the absence of the C2-C3 double bond on hydroxylated flavonoids results in a loss of effect on both the cell lines, while the higher activity of tangeretin compared with 7,3'-dimethylhesperetin suggests that the presence of at least three adjacent methoxyl groups confers a more potent antiproliferative effect.

Animals↗
PubMed2001

Seawater-atmosphere O(2) exchange rates in open-top laboratory microcosms: application for continuous estimates of planktonic primary production and respiration.

Seawater-atmosphere O(2) exchange rates were experimentally measured in open-top laboratory microcosms. The objective was to establish the relationships between turbulence and oxygen transfer velocity, and thus correct continuously measured day-night changes in dissolved oxygen as estimates of planktonic primary production and respiration. After saturating 15-l sterile seawater microcosms with an oxygen-poor gas mix (4.9% O(2), 95.1% N(2)), the microcosms were left to equilibrate with the atmosphere under different turbulence conditions. The rate of increase in dissolved O(2) was measured at 15-min intervals with polarographic-pulsed electrodes and the corresponding values of the oxygen transfer velocity (the K(O(2)) constant for the different turbulence conditions) were determined. After pooling these and literature data obtained in similar experimental conditions, the relation between epsilon (turbulent kinetic energy dissipation rates) and K(O(2)) was determined. Theoretical K(O(2)) values were also calculated using semi-empirical models in which oxygen transfer velocity (K(O(2))) is related to wind velocity. Theoretical, wind related K(O(2)) values were significantly higher than the experimental ones, and as a consequence overestimate primary production and underestimate respiration rates, even resulting in nocturnal O(2) increase. The magnitude of the differences between experimentally derived and theoretically calculated oxygen transfer velocity, precludes the use of wind-derived equations to calculate K(O(2)) in meso- and microcosms experiments not affected by wind, while the equation obtained relating experimental epsilon and K(O(2)) provides statistically reliable estimations of primary production and respiration.

Journal Article↗
PubMed2000

Oral Cerebrolysin enhances brain alpha activity and improves cognitive performance in elderly control subjects.

Cerebrolysin is a porcine brain derived peptide preparation with potential neurotrophic activity. The effects of a single oral dose of the Cerebrolysin solution (30 ml) on brain bioelectrical activity and on cognitive performance were investigated in healthy elderly people. A single oral dose of Cerebrolysin induced a progressive increase in relative alpha activity power from 1 to 6 hours after treatment in almost all the brain electrodes in elderly control subjects. As compared with baseline alpha power (45.8+/-9.5%), the increase in relative alpha activity in the left occipital electrode (O1) reached significant values at 1 hour (57.2+/-8.5%; p < 0.05), 3 hours (59.4+/-7.6%; p < 0.05) and 6 hours (63.4+/-9.8%; p < 0.05) after Cerebrolysin administration. Enhancement in relative alpha power was accompanied by a generalized decrease in slow delta activity that was maximum at 6 hours after Cerebrolysin intake. A significant improvement in memory performance, evaluated with items of the ADAS cog, was also found in elderly people taken a single dose of oral Cerebrolysin (6.9+/-1.0 errors at baseline versus 4.9+/-1.0 errors after treatment; p < 0.01). This memory improvement was more evident in recognition (2.8+/-0.6 errors vs. 1.5+/-0.7 errors; p < 0.05) than in recall tasks (4.1+/-0.5 errors versus 3.4+/-0.5 errors; ns). These data indicate that Cerebrolysin potentiates brain alpha activity, reduces slow EEG delta frequencies and improves memory performance in healthy elderly humans, suggesting that this compound activates cerebral mechanisms related to attention and memory processes. According to the present results, it seems that oral Cerebrolysin might be useful for the treatment of memory impairment and brain damage in eldely subjects with or without neurodegenerative disorders.

Administration, Oral↗
PubMed2000

Antioxidant activity and radioprotective effects against chromosomal damage induced in vivo by X-rays of flavan-3-ols (Procyanidins) from grape seeds (Vitis vinifera): comparative study versus other phenolic and organic compounds.

The quantitative distribution of several flavan-3-ols was determined using HPLC in a grape (Vitis vinifera) seed extract (GSE) of four cultivars grown in the region of Murcia. Polymer >/= C(4) units made up the largest group of procyanidins in the GSE (90.92%, expressed as HPLC % area). The antioxidant activity of GSE and other reference compounds was investigated by measuring their ability to scavenge the ABTS(*)(+) radical cation (TEAC). The most effective compounds were, in order: GSE > rutin > (+)-catechin > diosmin >/= ascorbic acid. The radioprotective effects of GSE and other reference compounds were determined by using the micronucleus test for anticlastogenic activity, any reduction of the frequency of micronucleated polychromatic erythrocytes (MnPCEs) being evaluated in the bone marrow of mouse exposed to X-rays. The most effective compounds were, in order: GSE > rutin > dimethyl sulfoxide (DMSO) > ascorbic acid > 6-n-propyl-2-thiouracil-6c (PTU) > diosmin. The higher ABTS(*)(+) scavenging capacity and anticlastogenic activity of GSE can be explained, structurally, by the high number of conjugated structures between the catechol groups in the B-rings and the 3-OH free groups of the polymeric polyphenolic skeleton and, in addition, by the stability of the aroxyl flavonoid radical generated in the above processes.

Animals↗
PubMed1999

Double-blind placebo-controlled study with citicoline in APOE genotyped Alzheimer's disease patients. Effects on cognitive performance, brain bioelectrical activity and cerebral perfusion.

Cytidine 5'-diphosphocholine (citicoline) is a an endogenous intermediate in the biosynthesis of structural membrane phospholipids and brain acetylcholine. Citicoline has been extensively used for the treatment of neurodegenerative disorders associated with head trauma, stroke, brain aging, cerebrovascular pathology and Alzheimer's disease. In this study we have investigated the efficacy and safety of the treatment with citicoline versus placebo in patients with Alzheimer disease. Thirty patients (age = 73.0 +/- 8.5 years; range = 57-87 years) with mild to moderate senile dementia (GDS: stages 3-6) of the Alzheimer type were included in a double-blind, randomized and placebo-controlled clinical trial. After a 2-week period of drug washout, patients were treated with i) placebo (n = 17; age = 73 +/- 5 years) or ii) 1,000 mg/day of citicoline (n = 13; age = 76 +/- 9 years) for 12 weeks (84 days). Examinations were done at baseline (T0) and after the 12 weeks of treatment (T12). As compared to placebo, citicoline improved cognitive performance in Alzheimer's disease patients with APOE E4 (ADAS: difference between groups = -3.2 +/- 1.8 scores, p < 0.05; ADAS-cog: difference between groups = -2.3 +/- 1.5, ns); and this improvement on cognition was more pronounced (ADAS, p < 0.01; ADAS-cog: difference between groups = -2.8 +/- 1.3, p < 0.06) in patients with mild dementia (GDS < 5). Citicoline also increased cerebral blood flow velocities in comparison with placebo (p < 0.05) when transcranial Doppler recordings from both hemispheres were considered together, as well as diastolic velocity in the left middle cerebral artery (p < 0.05). Patients treated with citicoline showed an increase in the percentage of brain bioelectrical activity of alpha (occipital electrodes) and theta type (left side electrodes), accompanied by a decrease in relative delta activity particularly marked in the left temporal lobe. Significant differences with respect to placebo (p < 0.05) were observed for theta activity in several fronto-parieto-temporal electrodes of the left hemisphere. Treatment with citicoline tended to reduce serum IL-1 beta levels, mainly after 4 weeks of administration, with no modified blood histamine content. In addition, neither adverse side effects nor alterations in biological and hematological parameters were induced by citicoline. The present data indicate that citicoline (1,000 mg/day) is well tolerated and improves cognitive performance, cerebral blood perfusion and the brain bioelectrical activity pattern in AD patients. According to our results, it seems that citicoline might be a useful treatment in Alzheimer's disease, and that the efficacy of this compound is greater in patients with mild mental deterioration and/or bearing the epsilon 4 allele of the APOE.

Aged↗
PubMed1997

[The evaluation of women's health promotion services: the internal client, the external client].

OBJECTIVES: To find the opinion of internal and external customers of the Women's Health Promotion Services; to obtain information about the perceptions and suggestions of both midwives and users of the service. DESIGN: An observational study of the qualitative evaluation of a service provided in Primary Health Care, through an open questionnaire to midwives and focus groups with users. SETTING: Health Area 4 in the Community of Valencia. PARTICIPANTS: 15 midwives from Health Area 4, 3 groups of women using the Pregnancy Follow-up Programme and 3 groups from the Programme of Integrated Care for climacteric women, coming from two Health Districts, one urban and one rural. MAIN RESULTS: For midwives, coordination with general practitioners was better in the urban setting, and with Family Planning Centres in the rural one. Absence of team work with gynaecologists, and gynaecologists' failure to value midwives' work, were identified as problems. CONCLUSIONS: Different patterns for the organisation and use of women's health promotion services were identified between the urban and rural setting. The problems of coordination identified by the midwives are not perceived as such by the service's users, who evaluated as satisfactory the Primary Care services received.

Adolescent↗
PubMed1994

Laurin-Sandrow syndrome (mirror hands and feet and nasal defects): description of a new case.

A child with complete syndactyly of cup shaped hands and mirror polysyndactyly of the feet, together with a nasal defect, was identified out of a total of 1,031,439 livebirths. She had a pattern of multiple congenital anomalies which was similar to that first described by Laurin et al in 1964 and by Sandrow et al in 1970. Two more cases with a similar pattern of congenital anomalies have recently been published so this is the fifth reported case with this constellation.

Abnormalities, Multiple↗
PubMed1990

Effects of radiation on rabbit thyroid gland ultrastructure.

The ultrastructure of irradiated rabbit thyroid gland (0 Gy, as control, 4 Gy, 8 Gy, 12 Gy, 16 Gy and 20 Gy X-ray) is studied. The thyroid gland of the control group shows ultrastructural features similar to those described in other mammals. Modifications in follicular ultrastructure and interfollicular connective tissue ultrastructure as well as the presence of small thyroid follicles, probably neoformed, are found to be dose-dependent. Follicular epithelium varies from simple cuboidal to simple squamous, the latter being characteristic of the highest X-ray dose. Follicular cells show numerous cytoplasmic light vesicles and a very extensive rough endoplasmic reticulum consisting of vacuolated cisternae. Sloughed cells are present at 8 Gy. A well-developed interstitial glandular tissue consisting of extensive extracellular matrix, abundant collagen fibres and dilated, irregularly outlined capillaries are also present.

Animals↗
PubMed1989

Study of postmortem blood circulation.

The objective of this work was to study the postmortem redistribution of blood volumes and its influence of the distribution of substances of different molecular weight (194.2 and 150,000 Da). Lipiodol Ultrafluide, Omnitrast, or a radioisotopic mixture of aminohippuric acid and human IgG were injected into the left ventricle of a total of 20 rabbits divided into three groups. Our results demonstrate the importance of related factors, including left ventricular postmortem contraction, the arterial vascular bed, diffusion processes connected to the physicochemical characteristics of the substances, and the anatomical distribution of the vessels. Postmortem diffusion of aminohippuric acid to the urine was observed.

Angiography↗