PubMed Health⌕ Search

Biomedical subjects

R Velasco

Publications and source records attributed to R Velasco.

At least 19 recordsLinked to original sources
PubMed2005

Comparative analysis of expressed sequence tags from different organs of Vitis vinifera L.

Expressed sequence tags (ESTs) are providing a valuable approach to sampling organism-expressed genomes, especially when studying large genomes such as those of many plants. We report on the comparison of 8,647 ESTs generated from six different grape (Vitis vinifera L.) organs: berry, root, leaf, bud, shoot and inflorescence. Clustering and assembly of these ESTs resulted in 4,203 unique sequences and revealed that at this level of EST sampling, each organ shares a low percentage of transcripts with the others. To define organ relationships based on EST counts, we calculated a distance matrix of pairwise correlation coefficients between the libraries which indicated bud, inflorescence and shoot as a group distinct from the other organs considered in this study. A putative function was identified for about 85% of the unique sequences. By assigning them to specific functional classes, we were able to highlight strong differences between organs in the metabolism, protein biosynthesis and photosynthesis categories. This grape EST collection has also proven to be a valuable source for the development of 'functional' simple sequence repeats (SSRs) markers: a total of 405 SSRs have been identified. EST sequences and annotation results have been organised in the IASMA-grape database, freely available at the address http://genomics.iasma.it.

DNA, Complementary↗
PubMed2005

Construction and characterization of BAC libraries from major grapevine cultivars.

Genome projects were initiated on grapevine (Vitis vinifera L., 2n=38, genome size 475 Mb) through the successful construction of four bacterial artificial chromosome (BAC) libraries from three major cultivars, Cabernet Sauvignon (Cabernet S), Syrah and two different clones of Pinot Noir (Pinot N). Depending on the library, the genome coverage represented 4.5-14.8 genome equivalents with clones having a mean insert size of 93-158 kb. BAC pools suitable for PCR screening were constructed for two of these BAC libraries [Cabernet S and Pinot N clone (cl) 115] and subsequently used to confirm the genome coverage of both libraries by PCR anchoring of 74 genetic markers sampled from the 19 linkage groups. For ten of these markers, two bands on separate BAC pools were differentiated that could correspond either to different alleles or to a duplication of the locus being studied. Finally, a preliminary assessment of the correspondence between genetic and physical distances was made through the anchoring of all the markers mapped along linkage group 1 of the V. vinifera genetic map. A pair of markers, 2.1 cM apart, anchored the same BAC clones, which allowed us to estimate that 1 cM corresponded in this particular region to a maximum length of 130 kb.

Chromosome Mapping↗
PubMed2004

Cloning and linkage mapping of resistance gene homologues in apple.

Apple ( Malus x domestica Borkh.) sequences sharing homology with known resistance genes were cloned using a PCR-based approach with degenerate oligonucleotide primers designed on conserved regions of the nucleotide-binding site (NBS). Sequence analysis of the amplified fragments indicated the presence of at least 27 families of NBS-containing genes in apple, each composed of several very similar or nearly identical sequences. The NBS-leucine-rich repeat homologues appeared to include members of the two major groups that have been described in dicot plants: one possessing a toll-interleukin receptor element and one lacking such a domain. Genetic mapping of the cloned sequences was achieved through the development of CAPS and SSCP markers using a segregating population of a cross between the two apple cultivars Fiesta and Discovery. Several of the apple resistance gene homologues mapped in the vicinity, or at least on the same linkage group, of known loci controlling resistance to various pathogens. The utility of resistance gene-homologue sequences as molecular markers for breeding purposes and for gene cloning is discussed.

Amino Acid Sequence↗
PubMed2002

Molecular linkage maps of Vitis vinifera L. and Vitis riparia Mchx.

Two linkage maps for grape (Vitis spp.) have been developed based on 81 F(1) plants derived from an interspecific cross between the wine cultivar Moscato bianco (Vitis vinifera L.) and a Vitis riparia Mchx. accession, a donor of pathogen resistance traits. The double pseudotest-cross mapping strategy was applied using three types of molecular markers. The efficiency of SSRs to anchor homologous linkage groups from different Vitis maps and the usefulness of AFLPs in saturating molecular linkage maps were evaluated. Moreover, the SSCP technique was developed based on sequence information in public databases concerning genes involved in flavonoid and stilbene biosynthesis. For the maternal genetic map a total of 338 markers were assembled in 20 linkage groups covering 1,639 cM, whereas 429 loci defined the 19 linkage groups of the paternal map which covers 1,518 cM. The identification of 14 linkage groups common to both maps was possible based on 21 SSR and 19 AFLP loci. The position of SSR loci in the maps presented here was consistent with other published mapping experiments in Vitis.

Base Sequence↗
PubMed2002

[Nocturnal oxymetry in patients with amyotrophic lateral sclerosis: role in predicting survival].

Death is the most important end point along the course of amyotrophic lateral sclerosis (ALS). It is commonly attributed to a respiratory failure in relation with a restrictive respiratory disorder. However, in clinical practice, it is frequent to observe that death has not direct relation with the values of the respiratory function, at least measured with vital capacity. It is also frequent that relatives report sudden death during nocturnal sleep. All these features raised the question of the possible relation between death and nocturnal oxymetry in ALS patients. In a prospective study, we studied 69 ALS patients. We recorded demographic data, clinical parameters as manual muscle testing and functional scales, various parameters of oxymetry measured by pulse oxymetry recorded during night, slow vital capacity and survival time. There is a strong correlation between survival time measured by Kaplan Meier curves and log rank and the mean nocturnal saturation. We determined 93 mmHg as a threshold value. Below this threshold, mean survival time was 7.5+/-1.6 months and above it was equal to 18.5+/-1.5; relative risk was 3.31. These data confirm the importance of nocturnal oxymetry on survival in ALS patients both in clinical practice and in view of therapeutic trials.

Aged↗
PubMed2000

Acute and subchronic effects of pimozide on isolation-induced aggression in male mice.

The aim of this study was to examine the effects of pimozide (0.25-1.25 mg/kg), administered acutely or subchronically for 10 days, on agonistic behavior elicited by isolation in male mice. Individually housed mice were exposed to anosmic "standard opponents" 90 min after pimozide injections, and the encounters were videotaped and evaluated using an ethologically based analysis. 3. After acute treatment pimozide did not affect significantly aggression and immobility. However, mice treated subchronically with pimozide (0.75 and 1.25 mg/kg) showed a significant reduction in offensive behaviors (threat and attack) and an increase of immobility (1.25 mg/kg). The antiaggressive and motor actions of pimozide were more marked after subchronic treatment than after acute treatment. It might reflect an accumulation of the drug over time, an effect also described with other neuroleptics such as amisulpride.

Aggression↗
PubMed1998

Gene structure and expression analysis of the drought- and abscisic acid-responsive CDeT11-24 gene family from the resurrection plant Craterostigma plantagineum Hochst.

In order to understand the molecular mechanisms which are responsible for desiccation tolerance in the resurrection plant Craterostigma plantagineum Hochst. a thorough analysis of the CDeT11-24 gene family was performed. CDeT11-24 comprises a small gene family whose genes are expressed in response to dehydration, salt stress and abscisic acid (ABA) treatment in leaves. The gene products are constitutively expressed in roots and disappear only when the plants are transferred to water. It is therefore suggested that the proteins are involved in sensing water status. The predicted proteins are very hydrophilic; they share some features with late-embryogenesis-abundant proteins, and sequence similarities were found with two ABA- and drought-regulated Arabidopsis genes. The analysis of beta-glucuronidase reporter genes driven by the CDeT11-24 promoter showed high activity in mature seeds in both transgenic Arabidopsis and tobacco. In vegetative tissues the promoter activity in response to ABA was restricted to young Arabidosis seedlings. The responsiveness to ABA during later developmental stages was regained in the presence of the Arabidopsis gene product ABI3. Dehydration-induced promoter activity was only observed in Arabidopsis leaves at a particular developmental stage. This analysis indicates that some components in the signal transduction pathway of the resurrection plant are not active in tobacco or Arabidopsis.

Abscisic Acid↗
PubMed1998

Slipped capital femoral epiphysis: a long-term follow-up study after open reduction of the femoral head combined with subcapital wedge resection.

Sixty-six hips of 65 patients with moderate to severe slipped capital femoral epiphysis were treated by open reduction of the femoral head. In 60 hips this procedure was combined with a cuneiform subcapital wedge resection of the femoral neck according to the technique described by Dunn (14). Avascular necrosis occurred in seven cases, and chondrolysis was evident in eight hips. In the 48 hips with a follow-up time of more than 10 years (M = 20.6), the results were classified as good (normal hip) in 22, moderate in 16, and poor in 10 hips. Compared with the natural disease course, the long-term outcome appears to be improved by open reduction of the femoral head, with 60% of the hips free of degenerative changes and 19% with mild osteoarthrosis. Analysis of individual gliding angles and subcapital correction depending on the direction of the slip should lead to restoration of near-normal anatomic conditions or a normal hip function.

Adolescent↗
PubMed1997

Structural analysis of rDNA in the genus Nicotiana.

The nucleotide sequence of the intergenic spacer (IGS) region between the 25S and the 18S rRNA coding regions has been determined for tobacco (Nicotiana tabacum). The IGS (5140 bp in length) can be subdivided into several regions (I-VII) two of which, upstream and downstream of the putative transcription initiation site (TIS), contain prominent subrepeats (A and C). The unique sequence in the central part of the IGS (region IV) preceding the TIS is extremely AT-rich. The distance from the putative TIS to the 5' end of the 18S rRNA gene is 3005 bp. The IGS sequences are compared with potato (Solanum tuberosum) and tomato (Lycopersicon esculentum) IGS. Restriction mapping of 13 Nicotiana species shows that considerable rDNA repeat length heterogeneity in this genus is probably due to different numbers of A and C subrepeats.

Base Composition↗
PubMed1996

Charge movement in overstretched amphibian skeletal muscle cut fibers.

Membrane current experiments were done in the absence of any permeable ion (except calcium) and the presence of TTX (tetrodotoxin) and TEA+ (tetraethylammonium) in the external solution and caesium in the internal solution at two different sarcomere lengths (3.8 and 4.56 microns) in skeletal muscle fibers of frog (pipiens). Single cut fibers were voltage-clamped in a double Vaseline gap apparatus, and intramembrane charge movement and slow calcium currents were measured. In order to obtain the charge movement, a conventional control was used (the response to a negative pulse) obtained in normally polarized fiber. A descriptive analysis of the results shows us that at 3.8 microns the fibers respond with slow calcium current and charge movement with the characteristics of charge 1 (Q1), but at a sarcomere length of 4.56 microns, just a slow calcium current is obtained. The absence of intramembrane charge movement in overstretched fibers could suggest a modification in the transverse tubular system geometry obscuring the charge movement phenomenon (the linear membrane capacity in stretched fibers was 13.10 micro F/cm2 as average for 5 fibers and in overstretched ones was 13.61 micro F/cm2 as average for 11 fibers). The presence of slow calcium current in this condition (overstretched fiber) means an electrical connection of the tubule with superficial membrane and suggests that the charge movement does not correspond to gating of the "L" type calcium channel.

Animals↗
PubMed1995

[Epiphysiolysis of the femoral head--can surgery prevent later arthritis?].

Slipped capital femoral epiphysis is one of the few orthopaedic emergencies. All orthopaedic surgeons agree that operation is the treatment of choice. In early stages, complete healing is possible. Fixation in situ is sufficient. If there is more severe dislocation of the head of the femur, the results become worse. More sophisticated and more difficult interventions aim at correction of the deformity, which may be a preliminary stage ['prearthrosis'] of osteoarthritis later in life. According to the extent of the slip, the surgeon may choose among different operations. The decision in a particular case is not easy. Complications are relatively frequent and sometimes severe. Long-term control show the late results and can thereby give guidelines for the surgeon's choice. Early diagnosis, however, is still decisive for a good prognosis in later life. As the disease is rather rare, the doctor who sees the patient first must be aware of it. Even at an early stage diagnosis can always be made on the basis of history, clinical findings and two X-rays.

Bone Nails↗
PubMed1994

Dehydration and ABA increase mRNA levels and enzyme activity of cytosolic GAPDH in the resurrection plant Craterostigma plantagineum.

We report the identification of a full-length cDNA clone encoding cytosolic glyceraldehyde-3-phosphate dehydrogenase (GAPDH, EC 1.2.1.12) in the desiccation-tolerant plant Craterostigma plantagineum. The DNA sequence of the cDNA clone is homologous to cytosolic GAPDH cDNAs from other higher plants. The GAPDH transcript increases rapidly in abundance during dehydration or abscisic acid (ABA) treatment. The increase in mRNA levels is directly correlated with higher protein and enzyme levels. These results imply that enhanced rates of glycolysis are one of the immediate cellular responses to water deficit. This may be a mechanism by which the plant cell prepares for a demand of ATP and NADH2 during recovery.

Abscisic Acid↗
PubMed1994

[Prognosis of spongiosa-plasty of the fractured tibial shaft].

Records of 97 patients who had undergone a total of 171 cancellous bone grafting procedures from 1971 to 1988 were analysed with respect to promotion of bony healing. It was found that 50 patients had undergone 1 grafting procedure each in the tibia, while 47 patients had each undergone 2-5 bone grafting procedures. Therefore only every second procedure at best could be considered as successful. Predictors for unsuccessful grafting were found to be large bone defects, poor vascularization and, especially, infection. Primary grafting was related to more problems in terms of uneventful bone healing than was "postprimary" grafting after 3 and more weeks after accident. We therefore recommend delayed grafting in cases of fractures with soft tissue ruptures. In all cases of segmental bone loss multiple bone grafting procedures should now be carefully compared with the advantages of segmental bone transport techniques.

Adolescent↗
PubMed1993

The biologic activity of ACTH and related peptides on peripheral blood mononuclear cells is altered by the presence of dexamethasone.

We wished to determine whether the glucocorticoid hormone dexamethasone (dex), a potent modular of both pituitary-adrenal and immunologic activity, altered the effect of adrenocorticotropin-related peptides on activated peripheral blood mononuclear cells (PBMCs) and T-cells. PBMCs preactivated with Concanavalin A (Con A) and T-cells preactivated with phorbol 12,13 dibutyrate (PDB) plus phytohemagglutinin (PHA) were exposed to dex, ACTH, and related peptide sequences. Proliferation of cells was measured as was IL-2 in conditioned media. It was found that in the absence of dex only the peptide ACTH(18-39) altered proliferation of PBMCs while there was no effect of peptide on T-cells activated via protein kinase C-mediated pathways. Significant reversal of the inhibitory effect of dex on proliferation of PBMCs exposed to Con A was achieved with addition of ACTH(1-39) and ACTH(11-24), while IL-2 levels were unaffected by the addition of peptide. ACTH(18-39) and ACTH(11-24) enhanced the inhibitory effect of dex on T-cells activated with PDB plus PHA. These findings suggest that the biologic activity of ACTH on immune cells is altered when dexamethasone is present and under certain circumstances ACTH may protect the immunologic response from the inhibitory effects of elevated ambient glucocorticoids.

Adrenocorticotropic Hormone↗
PubMed1983

Glucagon and primary hyperlipidemias.

A reduction in glucagon secretion was found in a number of patients suffering from primary hyperlipidemias. This could be important in both the pathogenesis and classification of hyperlipidemias.

Glucagon↗
PubMed1979

Effects of galactose, glucose and fructose on carbohydrate-lipid metabolism.

Doses of glucose, galactose and fructose were administered orally and intravenously, while monitoring the levels of blood glucose, serum insulin, free fatty acids, cholesterol and triglycerides. Blood glucose increases when glucose is administered orally or intravenously, but does not vary significantly with any other sugar. The increase in insulinemia only with oral and intravenous glucose and with oral galactose is in agreement with the participation of intestinal factors in the determination of insulin secretion. The results obtained for free fatty acids with the various sugars may be due to the metabolic properties of each sugar. We found no significant variations in the levels of cholesterol and triglycerides, perhaps because of the short duration of the experiment.

Administration, Oral↗