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Biomedical subjects

J Royo

Publications and source records attributed to J Royo.

At least 19 recordsLinked to original sources
PubMed2005

[Cochlear implants in Aragón].

Cochlear implants are, actually, one of the major advances in the treatment for profound deafness. His use is, already, a routine in the daily practice of our specialty. Due to its special aspects, cochlear implants have to be done following a protocol that organizes and coordinates the different aspects of the diagnoses and treatment of profound deafness, in the different administrative and geographical fields. The health system in our country and the smale dimension of our area, has taken us to create and follow a special program in which all the available resources are used. Following this protocol, we have performed 63 cochlear implants, in the last 10 years. We show here the results and complications.

Adolescent↗
PubMed2002

[The child with attention deficit hyperactivity disorder (ADHD). Hyperkinetic multi-disciplinary therapeutic approach].

Attention deficit disorder has a high prevalence in the infant population: from 3 to 5% of children of school age and, it could be as high as 8.1 + 2.7% of children at ten years of age, according to a study in the autonomous community of Valencia. It is a persistent problem whose manifestations can change in the course of its development, from pre-school age to adult life. In this paper we review the disorder in its epidemiological and etiological aspects, its natural history and its prognosis, as well as its diagnosis and treatment. We set out our experience with children and their families in two primary care paediatric units of the Navarra health service in two different settings - rural and urban. Finally, we draw attention to some of the difficulties faced in dealing with this disorder in a reasonable way.

English Abstract↗
PubMed2002

[Depressive disorders in children and adolescents].

Depressive disorders in children and adolescents are marked by core symptoms similar to those seen in adults, although symptom expression varies greatly with developmental stage. These disorders are common, chronic, and recurrent, and they are often associated with comorbid psychiatric conditions and poor prognosis that can be alleviated by early identification and treatment. The psychiatric assessment of depressed children and adolescents can be difficult and must be performed by an expert clinician. Recent research into the treatment of depression in children and adolescents has been focused on the effectiveness of cognitive-behavioural therapy and selective serotonin reuptake inhibitors.

English Abstract↗
PubMed2001

Influence of remote substituents on the equatorial/axial selectivity in the monooxygenation of methylene C--H bonds of substituted cyclohexanes.

The reactivity of individual C--H bonds in the methyl(trifluoromethyl)dioxirane TFDO oxygenation of stereogenic methylene groups in conformationally homogeneous monosubstituted cyclohexanes (2) has been determined. The unexpectedly high occurrence of O-atom insertion into C--H(ax) bonds suggests an in plane trajectory attack in the oxygenation while the diastereoselectivity of the reaction is qualitatively interpreted on the basis of the distinct hyperconjugative stabilization by the substituent of diastereomeric transition states due to long-range through bond interactions.

Journal Article↗
PubMed2000

A maize homologue of the bacterial CMP-3-deoxy-D-manno-2-octulosonate (KDO) synthetases. Similar pathways operate in plants and bacteria for the activation of KDO prior to its incorporation into outer cellular envelopes.

The eight-carbon acid sugar 3-deoxy-d-manno-2-octulosonate (KDO) is an essential component of Gram-negative bacterial cell walls and capsular polysaccharides. KDO is incorporated into these polymers as CMP-KDO, which is produced in an unusual activation step catalyzed by the enzyme CMP-KDO synthetase. CMP-KDO synthetase activity has traditionally been considered exclusive to Gram-negative bacteria. CMP-KDO synthetase inhibitors attract great interest owing to their potential as selective bactericides. The sugar KDO is also a component of the rhamnogalacturonan II pectin fraction of the primary cell walls of most higher plants and of the cell wall polysaccharides of some green algae. However, the metabolic pathway leading to its incorporation into the plant cell wall is unknown. This paper describes the isolation and characterization of a maize gene, which codes for a protein very similar in sequence and activity to prokaryotic CMP-KDO synthetases. Remarkably, the maize gene can complement a CMP-KDO synthetase (kdsB) Salmonella typhimurium mutant defective in cell wall synthesis. ZmCKS activity is novel in eukaryotes. The evolutionary origin of ZmCKS is discussed in relation to the high degree of conservation between the plant and bacterial genes and its atypical codon usage in maize.

Amino Acid Sequence↗
PubMed2000

Hyperconjugative Control by Remote Substituents of Diastereoselectivity in the Oxygenation of Hydrocarbons.

The oxidation of 2-substituted adamantanes (2) with TFDO (1) is reported. The data show a stereodifferentiation of the chemical environments induced by remote electron-withdrawing substituents which produces remarkable Z/E diastereoselectivity in the oxidation of the tertiary C(5)-H and C(7)-H bonds. The results show a bell-shaped correlation between the Z/E stereoselectivity and the substituent constant sigma(I), which is interpreted in terms of hyperconjugative stabilization of the diastereomeric transition states.

Journal Article↗
PubMed1999

Antisense-mediated depletion of a potato lipoxygenase reduces wound induction of proteinase inhibitors and increases weight gain of insect pests.

De novo jasmonic acid (JA) synthesis is required for wound-induced expression of proteinase inhibitors and other defense genes in potato and tomato. The first step in JA biosynthesis involves lipoxygenase (LOX) introducing molecular oxygen at the C-13 position of linolenic acid. We previously have shown that, in potato, at least two gene families code for 13-LOX proteins. We have now produced transgenic potato plants devoid of one specific 13-LOX isoform (LOX-H3) through antisense-mediated depletion of its mRNA. LOX-H3 depletion largely abolishes accumulation of proteinase inhibitors on wounding, indicating that this specific LOX plays an instrumental role in the regulation of wound-induced gene expression. As a consequence, weight gain of Colorado potato beetles fed on antisense plants is significantly larger than those fed on wild-type plants. The poorer performance of LOX-H3-deficient plants toward herbivory is more evident with a polyphagous insect; larvae of beet armyworm reared on the antisense lines have up to 57% higher weight than those fed on nontransformed plants. LOX-H3 thus appears to regulate gene activation in response to pest attack, and this inducible response is likely to be a major determinant for reducing performance of nonspecialized herbivores. However, the regulatory role of LOX-H3 is not caused by its involvement in the wound-induced increase of JA, as wild-type and LOX-H3 deficient plants have similar jasmonate levels after wounding. LOX-H3-deficient plants have higher tuber yields. The apparent effect of suppressing the inducible defensive response on plant vigor suggests that it may pose a penalty in plant fitness under nonstress situations.

Agrobacterium tumefaciens↗
PubMed1999

Evidence for factors regulating transfer cell-specific expression in maize endosperm.

In maize, a layer of basal endosperm cells adjacent to the pedicel is modified for a function in solute transfer. Three genes specifically expressed in this region, termed the basal endosperm transfer layer (BETL-2 to -4), were isolated by differential hybridization. BETL-2 to -4 are coordinately expressed in early and mid-term endosperm development, but are absent at later stages. BETL-2 to -4 coding sequences all predict small (< 100 amino acids), secreted, cysteine-rich polypeptides which lack close relatives in current database accessions. BETL-3 and BETL-1 display some sequence similarities with each other and to plant defensins. BETL-2 to -4 promoter regions were isolated and compared, revealing the presence of a promoter-proximal microsatellite repeat as the most highly conserved sequence element in each sequence. Electrophoretic mobility shift assays (EMSA) showed that specific BETL-2 to -4 promoter fragments competed for binding to the same DNA-binding activity in nuclear extracts prepared from maize endosperm. Although BETL-2 to -4 are only expressed in basal endosperm cells, the DNA-binding activities detected were of two types: distal endosperm-specific, or present in both basal and distal endosperm extracts. On the basis of these findings, a model to account for the coordinate regulation of BETL genes in endosperm cells is proposed.

Amino Acid Sequence↗
PubMed1997

[Sinus manifestations of the acquired immunodeficiency syndrome].

OBJECTIVE: We decided to review the different disorders which may affect the paranasal sinuses in the course of the acquired immuno-deficiency syndrome, and the most suitable treatment for them. DEVELOPMENT: Involvement of the paranasal sinuses is not particularly common in the acquired immuno-deficiency syndrome. The commonest disorder is sinusitis. Also seen are lymphomas no-Hodgkin, small cell, Burkitt's or no Burkitt and immunoblastic. Cases of Kaposi's sarcoma or malignant tumors such as a schwannoma may appear. In our hospital, an HIV+ patient presented with a frontal cerebral abscess which had developed from sinusitis of the whole left paranasal sphere. We have therefore reviewed 150 histories of HIV+ patients and the relevant literature available. CONCLUSIONS: Only in 3.3% of the HIV+ patients reviewed did sinusitis develop during the course of their illness. In one of these, there was intracranial spread of infection with the appearance of cerebral abscess following infection by Streptococcus milleri. We emphasize the review of the literature dealing with sinus pathology in these patients. On many occasions diagnosis was not made since it was masked by other infections. Cure is difficult and relapses are frequent in spite of suitable treatment and are associated with decline in immunocompetence.

Acquired Immunodeficiency Syndrome↗
PubMed1996

Characterization of three potato lipoxygenases with distinct enzymatic activities and different organ-specific and wound-regulated expression patterns.

Lipoxygenases are ubiquitous enzymes in eukaryotes. In plants, lipoxygenases are involved in the synthesis of the hormone jasmonic acid that regulates plant responses to wounding and, in addition, is an inducer of tuberization in potato. We have isolated potato lipoxygenase cDNA clones. From their deduced amino acid sequences, three distinct classes are defined (Lox1, Lox2, and Lox3). They are encoded in gene families that display organ-specific expression, lox1 being expressed mostly in tubers and roots, lox2 in leaves, and lox3 in leaves and roots. Consistent with their organ-specific expression pattern, Lox1 expressed in bacteria preferentially uses as substrate linoleic acid, abundant in membrane lipids of tubers, whereas linolenic acid, prevalent in leaves, is the preferred substrate for the other two classes of lipoxygenase. Analyses on reaction products of the enzymes expressed in bacteria reveal that Lox1 primarily produces 9- hydroperoxides. In contrast, the jasmonic acid precursor, 13-hydroperoxylinolenic acid, is the major product of the action of Lox2 and Lox3 on linolenic acid. Upon wounding, the levels of Lox2 and Lox3 transcripts rise markedly in leaves. While Lox3 mRNA accumulation peaks as early as 30 min after wounding, Lox2 shows a steady increase over a 24-h time course, suggesting different roles for these lipoxygenase isoforms in the synthesis of the plant hormone jasmonic acid.

Amino Acid Sequence↗
PubMed1996

A retrotransposon-like sequence linked to the S-locus of Nicotiana alata is expressed in styles in response to touch.

We have identified a family of repetitive sequences in the genome of Nicotiana alata named Tna1 (Transposon of N. alata). The first element we characterised was a genomic clone for the N. alata s6-ribonuclease (S6-RNase), a gene required for self-incompatibility in this species. The DNA sequence of this element resembles the integrase domain of retrotransposons of the gypsy class and is most similar to a retrotransposon from Lilium henryi. A transcript present in N.alata styles (self-incompatibility genotype S6S6) hybridized to Tna1 and accumulated in the style following either pollination or touching. This transcript was cloned from a cDNA library and was encoded by second, partial Tna1 elements. Neither the transcribed sequence nor the original Tna1 element contain an open reading frame or is likely to be able to transpose. The second element was mapped using a population of N.alata plants segregating for alleles of the self-incompatibility locus and is closely linked to the S6-allele. The Tna1 element is present in a number of Nicotiana species and appears to have been active at least twice during the evolution of this genus.

Amino Acid Sequence↗
PubMed1996

Isolation and promoter characterization of barley gene Itr1 encoding trypsin inhibitor BTI-CMe: differential activity in wild-type and mutant lys3a endosperm.

The gene Itr1, encoding trypsin inhibitor BTI-CMe, has been obtained from a genomic library of Hordeum vulgare L. The gene has no introns and presents in its 5'-upstream region 605 bp that are homologous to the long terminal repeats (LTR) of the 'copia-like' retro-transposon Bare-1. Functional analysis of the Itr1 promoter by transient expression in protoplasts derived from different barley tissues, has shown that in this system the Itr1 promoter retains its endosperm specifity and the trans-regulation mediated by the Lys3a gene. The proximal promoter extending 343 bp upstream of the translation initiation ATG codon is sufficient to confer full GUS expression and for endosperm specifity. In protoplasts derived from the lys3a mutant, Risø 1508, GUS activity was less than 5% of that obtained with the same constructs in the protoplasts of wild-type Bomi from which it derives. Gel retardation experiments, after incubation with proteins obtained from both types of endosperm nuclei, also show differential patterns. Possible reasons for these differences are discussed.

Amino Acid Sequence↗
PubMed1995

The promoter of the gene Itr1 from barley confers a different tissue specificity in transgenic tobacco.

Tissue-specific expression of the gene coding for trypsin inhibitor BTI-CMe in barley (Itr1) occurs during the first half of endosperm development. In transgenic tobacco, the Itr1 promoter drives expression of the beta-glucuronidase reporter gene not only in developing endosperm but also in embryo, cotyledons and the meristematic intercotyledonary zone of germinating seedlings. A promoter fragment extending 343 bp upstream of the translation initiation ATG codon was sufficient for full transgene expression, whereas, the proximal 83 bp segment of the promoter was inactive. Possible reasons for the differences in expression patterns are discussed.

Base Sequence↗
PubMed1994

Loss of a histidine residue at the active site of S-locus ribonuclease is associated with self-compatibility in Lycopersicon peruvianum.

Gametophytic self-incompatibility in the Solanaceae is controlled by a single, multiallelic locus, the S locus. We have recently described an allele of the S locus of Lycopersicon peruvianum that caused this normally self-incompatible plant to become self-compatible. We have now characterized two glycoproteins present in the styles of self-compatible and self-incompatible accessions of L. peruvianum: one is a ribonuclease that cosegregates with a functional self-incompatibility allele (S6 allele); the other cosegregates with the self-compatible allele (Sc allele) but has no ribonuclease activity. The derived amino acid sequences of the cDNAs encoding the S6 and Sc glycoproteins resemble sequences of other ribonucleases encoded by the S locus. The derived sequence for the Sc glycoprotein differs from the others by lacking one of the histidine residues found in all other S-locus ribonucleases. These findings demonstrate the essential role of ribonuclease activity in self-incompatibility and lend further weight to evidence that this histidine residue is involved in the catalytic site of the enzyme.

Alleles↗
PubMed1994

Unusual association of secondary tonsillar and cerebral tuberculosis.

The patient was a 50-year-old alcoholic man with a left palatine tonsillar ulcer. Histopathological and bacteriological studies established the diagnosis of tonsillar tuberculosis with asymptomatic advanced pulmonary tuberculosis and multiple cerebral supra- and infratentorial tuberculomas previously unnoticed.

Alcoholism↗