Biomedical subjects

E Valverde

Publications and source records attributed to E Valverde.

At least 19 recordsLinked to original sources

PubMed2004

Characteristics of Ryan White and non-Ryan White funded HIV medical care facilities across four metropolitan areas: results from the Antiretroviral Treatment and Access Studies site survey.

The Ryan White Comprehensive AIDS Resources Emergency Act 1990 (CARE Act) is one of the largest federal programmes funding medical and support services for individuals with HIV disease. Data that report services and gaps in service coverage from the organizational perspective are very limited. The Antiretroviral Treatment and Access Studies included a mail survey of 176 HIV medical care facilities in four US inner cities on clinic characteristics, services and practices, and patient characteristics. Characteristics of 143 (85%) responding Ryan White (RW) funded and non-RW funded facilities are described. RW funded facilities reported offering more services than non-funded facilities including evening/weekend hours (49% vs. 18%), transportation (71% vs. 22%), and on-site risk reduction counselling (88% vs. 55%). More RW funded facilities reported offering on-site adherence support services, such as support groups (44% vs. 12%), formal classes (20% vs. 2%), and pillboxes (83% vs. 43%), and served a larger proportion of uninsured patients (41% vs. 4%) than non-funded facilities. Our analysis showed that the RW funded HIV care facilities offered more clinic, non-clinic, and adherence support services than non-RW funded facilities, indicating that the disparities in services were still related to CARE Act funding, controlling for private-public facility type.

Adolescent↗

PubMed2001

Intestinal permeability in adult patients with growth hormone deficiency.

Pathological disruption of the intestinal mucosa increases the paracellular pathway, leading to an increase in the penetration of large molecules. Since growth hormone (GH) has a trophic intestinal effect, we used a double marker test to enable examination of intestinal permeability, which reflects the state of integrity of the intestinal mucosa. We recruited 22 adult patients, mean age 54+/-13.3 years, with GH deficiency due to partial or total hypopituitarism. None had received GH treatment at any time, although they were all in optimized replacement therapy. A control group was composed of 19 healthy age-matched relatives. The intestinal permeability test was performed with lactulose (5 g) and mannitol (1 g) after an oral load of 100 ml of aqueous solution. The urinary lactulose/mannitol ratio and the percentages of lactulose and mannitol excreted were determined on a 5-h urine collection. There were no significant differences between the patients and the control group in the lactulose/mannitol ratio (0.087+/-0.059 vs 0.077+/-0.064, respectively) or in the urinary excretion percentages of lactulose (0.067+/-0.048% vs 0.073+/-0.070%, respectively) or mannitol (5.127+/-3.269% vs 5.068+/-2.985%, respectively). In conclusion, no increase in intestinal permeability was detected in patients with GH deficiency, so that in spite of the known trophic effects of GH on the epithelial crypt cells, there was no intestinal hyperpermeability in these patients.

Adult↗

PubMed2001

Postnatal adaptation of brain circulation in preterm infants.

Global and regional postnatal cerebral circulatory changes in stable preterm infants were studied, and their relation to brain injury was assessed. Thirty-five preterm infants were studied on the first and second days of age. Cerebral blood flow (CBF) (mL/hg per min) and cerebral blood volume (CBV) (mL/hg) were measured using near-infrared spectroscopy. The cerebral blood flow velocity (cm/second) (peak systolic, diastolic flow, mean flow) and resistance index (RI) were determined in the internal carotid, anterior cerebral, and striate arteries by color Doppler flow imaging. Serial cerebral ultrasound studies were performed to detect changes in brain parenchymal echogenicity or intraventricular hemorrhage (IVH); the maximum severity of these findings was considered. CBF and cerebral blood flow velocity increased significantly with time, and such changes were independent of mean blood pressure, PO(2), PCO(2), hematocrit, or glycemia. In contrast, CBV and RI remained unchanged. According to the results of sonograms, no differences were found in postnatal CBF and cerebral blood flow velocity changes, regardless of whether patients had or did not have parenchymal lesions or IVH. However, higher CBV values were found on the second day in infants with IVH compared with infants without IVH. Early coupling of CBF and metabolic demands is independent of blood pressure. Improved venous return, instead of vasodilation, could be important in this adaptation.

Adaptation, Physiological↗

PubMed2000

Sex-dependent electrocardiographic pattern of cardiac repolarization.

BACKGROUND: Although sex-dependent differences in cardiac repolarization have been known for many years, few attempts have been carried out to define the individual contribution of each electrocardiographic (ECG) repolarization variable to the sex-dependent pattern. METHOD AND RESULTS: We analyzed several ECG repolarization variables that reflect both the duration and the rate of repolarization in 500 normal healthy subjects between the ages of 20 and 80 years (250 men and 250 women) and distributed into 5 groups according to age. Cardiac repolarization, measured in the precordial lead exhibiting the highest T-wave amplitude, was found to be shorter and faster in normal men compared with normal women (P <.001). The parameters with the highest individual weight in determining these sex differences were the J point and the ST angle, as indicated by nonlinear (logistic) multivariate regression analysis. CONCLUSION: We conclude that changes in the duration and rate of early repolarization are determinants for these sex-dependent ECG pattern differences.

Adult↗

PubMed2000

Sex differences on the electrocardiographic pattern of cardiac repolarization: possible role of testosterone.

BACKGROUND: Cardiac repolarization has been shown to be shorter and faster in men compared with women. In this study, we examined the electrocardiographic pattern of repolarization in patients with abnormal plasma levels of testosterone to gain insight into the role that this hormone plays in modulating repolarization. METHODS AND RESULTS: Repolarization was measured in 27 castrated men, 26 women with virilization, and 53 control subjects pair-matched for age and sex. Repolarization in castrated men was slower and longer than that of normal men. Women with virilization exhibited a shorter and faster repolarization than normal women and castrated men. These differences are the opposite of those found in the normal population. Finally, the changes observed in castrated men may be reverted by testosterone. CONCLUSIONS: We conclude that testosterone plays an important role in modulating cardiac repolarization.

Action Potentials↗

PubMed1999

Effect of the cyclo-oxygenase blocker ibuprofen on cerebral blood volume and cerebral blood flow during normocarbia and hypercarbia in newborn piglets.

Indomethacin modifies baseline cerebral haemodynamics and metabolism, as well as vasomotor adaptive responses. However, the significance of arachidonic acid metabolites in the regulation of cerebral circulation remains unclear. A study was made of the effect of inhibition of the cyclo-oxygenase pathway on baseline cerebral haemodynamics and CO2-induced vasodilation using the more specific cyclo-oxygenase blocker ibuprofen in a neonatal pig model. Two methods were used: radiolabelled microspheres to measure cerebral blood flow and near infrared spectroscopy to calculate absolute changes in cerebral blood volume. The relationship between CO2-induced changes in these two haemodynamic parameters was evaluated. Fifteen newborn piglets <7 d old received an i.v. infusion of either ibuprofen (30 mg/kg) (IB group, n = 8) or saline (control group, n = 7). Cerebral blood flow and absolute changes in cerebral blood volume were measured while the piglets were breathing room air at baseline and 30 min after infusion of ibuprofen or saline, and 15 min and 30 min after inducing hypercarbia. Global and regional cerebral blood flow (ml/hg/min) and absolute changes in cerebral blood volume (ml/hg) did not vary between baseline and 30 min after infusion of ibuprofen or saline. During hypercarbia, global and regional cerebral blood flow and absolute changes in cerebral blood volume increased significantly in both the ibuprofen and control groups (p < 0.01). The mean percentage increases in blood flow and blood volume at each measurement were almost identical, with approximately 90% of the increase in both parameters occurring after 15 min of hypercarbia, then reaching a plateau. However, we found no agreement between cerebral blood flow changes and absolute changes in cerebral blood volume. We conclude that ibuprofen did not alter either baseline cerebral circulation or physiological CO2-induced vasodilation in newborn pigs. We speculate that hypercarbic cerebral vasodilation could be caused either by mediators other than the cyclo-oxygenase metabolites of arachidonic acid or by a direct effect on vessel walls.

Analysis of Variance↗

PubMed1998

Informativeness of polymorphic markers for prenatal diagnosis of recessive dystrophic epidermolysis bullosa in Spanish families at risk.

DNA polymorphic markers are useful for the prenatal diagnosis of generalized recessive dystrophic epidermolysis bullosa (GRDEB) in families with at least one child affected with the disease. It is our policy to investigate families at risk using DNA polymorphic markers before a new pregnancy is intended, to inform about the real chances of offering an accurate prenatal diagnosis based on such DNA markers. We have analysed 10 Spanish families with at least one child affected with GRDEB with three different markers linked to the type VII collagen gene: the intragenic PvuII RFLP, and two markers mapped close to the COL7A1 gene, an MspI polymorphism belonging to the anonymous marker D3S2, and the microsatellite D3S1100. The PvuII marker was partially informative in two of 10 families, and was fully informative in three additional families; The MspI marker was partially informative in two of 10 families, and was fully informative in three additional families; it was not informative in five families. The D3S1100 microsatellite was partially informative in two out of 10 families, and fully informative in the other eight families. Combination of all three markers was shown to be partially informative in one family and fully informative in the remaining nine families. Using this combination of markers, we have inferred an accurate linkage-based prenatal diagnosis of GRDEB in four pregnancies. Surprisingly, the intragenic marker PvuII had a very limited usefulness, despite the results of previous studies; the microsatellite D3S1100 offered the best results for an eventual prenatal diagnosis of GRDEB. However, families at risk should be informed that extragenic markers may fail due to the possibility of recombination, estimated as 5% for D3S1100.

Collagen↗

PubMed1997

Lipid, protein, and calorie content of different Atlantic and Mediterranean fish, shellfish, and molluscs commonly eaten in the south of Spain.

We undertook a systematic evaluation of the lipid, protein, calorie, and fatty acid composition in 35 species of fish, shellfish and molluscs commonly consumed throughout the four seasons of the year in Andalusia, Spain. Using a portion of muscle tissue the following were measured in each study unit: total lipids (extraction using Folch's method and gravimetry), protein concentration (Kjehldal's method), total calories (direct calorimetry), and composition of fatty acids (gas chromatography). The lipid, protein, and different fatty acid concentrations found are presented in table form. There was a high degree of inter-species variability in the concentration of lipids and the various fatty acids. There was also a high degree of intra-species seasonal variability in some cases. The relative proportion of fatty acids was not independent of the total concentration of lipids, independently of the season studied. This systematic study of a large group of species shows that the cataloguing of fish as 'white' or 'blue' depends especially on the time of year they are captured. For example, in spring the mackerel (Scomber scombrus), a fish considered traditionally to be 'blue' (fatty), has the same lipid concentration as the dover sole (Solea vulgaris), commonly considered to be 'white' (little fat), and the sea pike (Merluccius merluccius) has a higher lipid concentration in autumn than the jack mackerel (Trachurus trachurus). Even greater differences existed when the fish were classified according to their richness in n-3 fatty acids. These differences in the total lipid concentration and the composition of fatty acids, as well as the inter-relations between them, may, under certain circumstances, be important for the calculation of dietary calories and nutritional values, and may explain the differences found between the various tables of food composition, as well as the divergent results in epidemiological studies on the association between fish in diets and various diseases, such as diabetes or ischaemic cardiopathy.

Animals↗

PubMed1997

An immunocytochemical and ultrastructural study of the larval anterior intestine of the frog Rana temporaria, with especial reference to endocrine cells.

Endocrine cells of the larval intestine of Rana temporaria tadpoles have been identified by argyrophilic, immunocytochemical and electron-microscopical techniques. Scarce endocrine cells have been found in both the short non-absorptive zone immediately following the stomach, and in the rest of the anterior intestine. Endocrine cells are frequently seen to extend a cytoplasmic process towards the lumen. Immunoreactivity for serotonin, somatostatin, bombesin and cholecystokinin-8 has been detected. According to the ultrastructural traits of the endocrine granules, three larval intestinal endocrine populations have been differentiated.

Animals↗

PubMed1996

Semiparametric approach to match probability calculations using single locus probes.

A semiparametric approach to match probability calculations using single locus probes has been developed and compared graphically with other standard methods by a one-sample simulation. The density functions obtained using this method are closer to the real distributions than those obtained by conventional approaches. Our method does not need to establish an arbitrary match threshold, which has been a source of problems in practical applications of standard methods. Moreover, it can be adjusted to any particular conditions by setting the experimental error and correlation of each laboratory. To assess the practical performance of this method we carried out a comparison experiment using a sample of 229 individuals analysed in duplicate.

Alleles↗

PubMed1996

Central nervous system vasculopathy in neonatal lupus erythematosus.

Central nervous system involvement in neonatal lupus erythematosus (NLE) has not been previously reported. We report four patients with NLE, all with complete congenital heart block and three with cerebral ultrasound and color Doppler flow imaging (CDFI) studies demonstrating evidence of associated vasculopathy in the gangliothalamic vasculature. CDFI confirmed blood flow through the affected vessels, indicating that blood flow was not compromised at this early stage. Short-term follow-up revealed no signs of progression of the vasculopathy, focal ischemia, gangliothalamic atrophy, or neurological impairment. Nevertheless, the implications of this finding with respect to the natural history of NLE remain to be defined, particularly in cases in which the disease develops into systemic lupus erythematosus later in life. Besides specific diagnostic studies for NLE, cerebral ultrasound, and CDFI studies are mandatory in all cases of complete congenital heart block, regardless of whether mothers are diagnosed as having connective-tissue disease or not. Neonates with signs of vasculopathy in the gangliothalamic region should be examined for NLE.

Autoantibodies↗

PubMed1996

Population data on the loci LDLR, GYPA, HBGG, D7S8, and GC in three southwest European populations.

Three Southwest European populations: Galicia (NW Spain), a mixed Spanish population from the rest of Spain (outside Galicia), and a population sample from the Coimbra area (Centre of Portugal) have been studied for the Low Density Lipoprotein Receptor (LDLR), Glycophorin A (GYPA), Hemoglobin G Gammaglobin (HBGG), D7S8 and Group Specific Component (GC). The allele and genotype frequencies found have been compared with other previously published data. All loci meet Hardy-Weinberg expectations in the three sampled populations. There was no evidence of association in any of the three population samples, between the five loci studied. No significant differences were found with Caucasian populations, nevertheless, significant differences were observed between our three population studies and the US SW Hispanic and African populations. The AmpliType PM DNA test greatly facilitates DNA testing in forensic laboratories, providing quick results and a good discrimination power from a single test.

DNA↗

PubMed1995

Allele frequency distribution of four PCR-amplified loci in the Spanish population.

The allele frequency distributions of four VNTR loci amplified by PCR have been studied in a population of 205 individuals from Spain. The loci analysed are D1S80 and three STRs: HUMTH01, HUMFES/FPS and HUMACTBF2 (SE33). The former was visualized in Metaphor agarose gels, and the STRs in sequencing polyacrylamide gels under denaturing conditions which could separate alleles with differences of a single base. This is of particular importance in the HUMTH01 locus, a tetrameric STR in which two alleles (9.3 and 10) were detected differing in a single base. Furthermore, HUMACTBP2 has at least 30 alleles, some of which may vary by as little as one base. At this locus a variation in the allele mobility was observed, depending on the electrophoretic conditions. For this reason, there should be careful consideration before this marker is accepted and validated as a common interlaboratory system. This paper does not include any comparison of the frequencies obtained for this locus with other recent studies. For the rest of the loci, the frequencies found have been compared with other published population studies; they show a degree of difference, particularly in the D1S80 locus. Finally, the systems were tested for Hardy-Weinberg equilibrium, and some statistical parameters of forensic interest were calculated.

Alleles↗

PubMed1995

Metamorphic changes in the stomach of the frog Rana temporaria tadpoles.

The histological transformation of amphibian stomach during metamorphosis was studied in the frog Rana temporaria. The earliest metamorphic changes occur shortly before regression of the cloacal piece of tail and appearance of forelegs. Autolysis of primary, larval epithelial cells and activity of phagocytes lead to regression of the apical mucosa, which is shed into the gastric lumen. Histogenesis takes place from the very beginning of metamorphosis in the basal region of the mucosa; undifferentiated, regenerative cells, arranged in small compact cords and surrounded by a thick basement membrane, give rise to secondary lining epithelium and glands. Lining epithelial cells differentiate into a typical mucosecretory epithelium. Oxyntic cells present in larval glands are substituted by both ion- and protein-secreting oxyntic-peptic cells. During metamorphosis, connective and muscular tissues markedly increase, a submucosa, not present in larval tadpoles, gradually develops. A muscularis mucosae is also formed and the muscular propria becomes thicker. At late metamorphosis, folded structures involving both mucosa and submucosa develop, increasing the luminal surface as in adults. Removal of the larval gastric mucosa and its replacement by a new, adult-type definitive one, together with development of peripheral connective and muscular tissues, account for metamorphosis of tadpole stomach.

Animals↗

PubMed1994

Possible implications of doxycycline-rifampin interaction for treatment of brucellosis.

We studied the possible interaction between rifampin and doxycycline in 20 patients with brucellosis treated randomly with either doxycycline and streptomycin or doxycycline and rifampin. The doxycycline levels in the plasma of patients in the group treated with rifampin were significantly lower than those in the plasma of patients treated with doxycycline and streptomycin. Furthermore, clearance in patients treated with rifampin was significantly higher than that in patients treated with doxycycline and streptomycin, and consequently, the elimination half-life and the area under the concentration-time curve were significantly lower. There was no therapeutic failure or relapse in the group treated with doxycycline and streptomycin, whereas 2 of 10 patients in the group treated with doxycycline and rifampin had a therapeutic failure or relapse. The plasma doxycycline levels had an inverse correlation with plasma rifampin levels. In the group treated with rifampin, those who were rapid acetylators had lower levels of doxycycline. In conclusion, combined treatment with rifampin reduces the levels of doxycycline in plasma. These data suggest that therapeutic failures or relapses may result from this interaction.

Adult↗

PubMed1993

Population genetics of three VNTR polymorphisms in two different Spanish populations.

Two different Spanish populations, one from Galicia (NW Spain) and the other from the rest of Spain, have been analyzed at three different hypervariable loci (YNH24, MS43a and MS31) using the EDNAP electrophoretic protocol and HinfI as restriction enzyme. Although the "rest of Spain" population is a clearly stratified population using classical blood groups, no evidence of stratification for these loci has been found and the differences to the Galician population were not significant, which suggests that a common Spanish population data-base could be possible. A semiparametric model is proposed for estimating frequencies, using the smoothed cross-validation of Hall et al. (1992) to calculate the size of the window utilized.

Alleles↗

PubMed1993

Immunocytochemical and ultrastructural characterization of endocrine cells and nerves in the intestine of Rana temporaria.

Endocrine cells have been identified in the intestine of the frog Rana temporaria after application of the Grimelius and Masson-Fontana techniques. These endocrine cells were examined using immunocytochemical techniques on paraffin and semithin sections for light microscopy. After testing 19 antisera, 12 immunoreactivities were identified. Numerous serotonin-, somatostatin- and GLP-1-immunoreactive cells; a moderate number of PYY-, glucagon-, VIP-, gastrin/CCK-immunoreactive cells and few human PP-, bombesin-, substance P- and neurotensin-immunoreactive cells were found. VIP- and met-enkephalin were identified in nerve fibers of the muscular layer. Using semithin-thin sections five types of endocrine cells (serotonin-, somatostatin-, gastrin/CCK-, glucagon- and bombesin-immunoreactive cells) have been characterized according to their immunocytochemical reaction and the ultrastructure of the secretory granules.

APUD Cells↗

PubMed1993

Structural study of the frog Rana temporaria larval stomach.

The gastric wall of Rana temporaria tadpoles consists of a well-developed mucosa and thin muscular and serosa layers. Three cellular types--mucous, ciliated and endocrine cells--make up the lining epithelium. Different types of endocrine cells exist. Argyrophylic endocrine cells can be recognized in semithin sections of plastic-embedded material while non-argyrophylic endocrine cells can only be identified under the electron microscope. Glands are composed mainly of well-differentiated oxyntic cells and, occasionally, scarce endocrine cells. Oxyntic cells show abundant mitochondria and smooth endoplasmic reticulum, but do not contain zymogen granules as do those present in adults. Secretory canaliculi with microvilli are also well-developed. The lamina propria contains numerous vascular sinuses and nerve bundles which innervate the endothelium and some endocrine cells. The neuroendocrine regulation of frog gastric functions seems therefore to have developed in young tadpoles. Nerve fibers also innervate the muscular propria, which is composed of a single layer of smooth muscle cells. Underlying the muscle, connective fibers and a flattened layer of mesothelial cells make up the serosa. In summary, the structure of the frog larval stomach shows a well-differentiated histological pattern, especially referring to surface epithelium and glands. Some of the histological traits will also be present in adult frogs while others are characteristic of the tadpole's stage.

Animals↗