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Biomedical subjects

J M Espinosa

Publications and source records attributed to J M Espinosa.

13 recordsLinked to original sources
PubMed2001

Transcriptional regulation by p53 through intrinsic DNA/chromatin binding and site-directed cofactor recruitment.

The tumor suppressor protein, p53, plays a critical role in mediating cellular response to stress signals by regulating genes involved in cell cycle arrest and apoptosis. p53 is believed to be inactive for DNA binding unless its C terminus is modified or structurally altered. We show that unmodified p53 actively binds to two sites at -1.4 and -2.3 kb within the chromatin-assembled p21 promoter and requires the C terminus and the histone acetyltransferase, p300, for transcription. Acetylation of the C terminus by p300 is not necessary for binding or promoter activation. Instead, p300 acetylates p53-bound nucleosomes in the p21 promoter with spreading to the TATA box. Thus, p53 is an active DNA and chromatin binding protein that may selectively regulate its target genes by recruitment of specific cofactors to structurally distinct binding sites.

Acetylation↗
PubMed1998

Indications and counterindications for cochlear implantation in children.

OBJECTIVE: This study is aimed to analyze the current indications and counterindications of cochlear implantation (CI) in children. STUDY DESIGN: This study reviews the children implanted in our institution looking specifically at the following aspects: 1) auditory criteria for candidate selection; 2) age at implantation; 3) educational environment; and 4) associated handicapping conditions. SETTING: Tertiary referral center with experience in CI since 1989 with inpatient and outpatient care. INTERVENTION: All children received a Mini Nucleus 22 CI device (Cochlear Limited, Australia) in a standard surgical procedure. RESULTS: Regarding auditory criteria, children with average hearing level of 100-105 dB HL are more likely to obtain benefit from a CI than from a hearing aid. The minimum age for CI should be as soon as there is a reliable diagnosis of bilateral profound hearing loss, while the maximum age for CI depends on strict selection criteria of candidates. The educational environment is of a great importance in the rehabilitation process, permitting a progressive change to oral communication. Our experience in CI of children with multiple handicapping conditions is limited to a case of a deaf-blind child who was implanted with a good performance. In the selection of these children it is mandatory to have extensive multidisciplinary evaluation. CONCLUSIONS: An experienced team is needed in the selection of children for CI. Candidates should meet anatomic criteria, have a reliable diagnosis of bilateral profound hearing loss, an evaluation of communication skills, and extensive neuropediatric and socioeducational evaluation.

Adolescent↗
PubMed1997

Use of distortion-product otoacoustic emissions for auditory evaluation in Menière's disease.

Otoacoustic emissions are a relatively new tool for assessment of inner ear function. We studied 65 patients diagnosed as having Menière's disease. In order to obtain and characterize responses at different frequencies we used distortion-product otoacoustic emissions (DPOAE). In unilateral cases, the difference in response between ears on the diseased and healthy sides was evident at all frequencies. In the former the result was lower than expected for a group of normally hearing subjects, while in the latter it was better than expected according to pure tone averages. Reduction in amplitude and increment in threshold of the DPOAE in the diseased ear was a significant finding and could be correlated to the stage of the disease. In those subjects treated with Betahistine after 1 year's follow-up, DPOAE testing showed the recovery of response at low frequencies and a reduction of its threshold at all frequencies studied.

Acoustic Stimulation↗
PubMed1992

[Program of care of disabled patients at a health center].

OBJECTIVE: To systematise primary attention to the disabled by means of a programme of specific action. To create a Risk Map for the problem of "abandonment of the elderly disabled". DESIGN: Retrospective descriptive study. SITE. El Palo Health Centre (Málaga). First two years of the programme (1989-1991). PATIENTS OR OTHER PARTICIPANTS: Patients with physical and/or mental disability attending to Centre to obtain services. The basic Primary Attention Team. Key informants, the Voluntary Social service. INTERVENTION: Activities: Recruitment strategies: Programme of Planned Home Visits (Subscribers' Register, Individualised Care Plan), Risk Map of Basic Area. RESULTS: 142 patients were included in the first year, and 203 in the second year, carrying out 4.66 and 5.95 programmed visits per patient per year, respectively. The Risk Map defined 28 areas ranked according to risk.

Catchment Area, Health↗
PubMedDate not supplied

MRNA encoding a putative RNA helicase of the DEAD-box gene family is up-regulated in trypomastigotes of Trypanosoma cruzi.

Differential display of mRNAs from Trypanosoma cruzi epimastigote and metacyclic trypomastigote stages showed several mRNA species differing in their expression level. The cDNA corresponding to one of these mRNAs was used as a probe in Northern blots and identified a RNA product of 2.6 kb with an expression level eight or more times higher in trypomastigotes than in epimastigotes. This probe was also used to screen a genomic library of T. cruzi CL Brener clone prepared in lambda FIX. A clone of about 15 kb was selected that, after partial sequencing, revealed an open reading frame of 688 amino acids encoding a deduced protein with similarity to RNA helicases of the DEAD-box gene family. The presence of the eight conserved motifs characteristic of the DEAD protein family was observed in the T. cruzi sequence, indicating that it corresponds to a putative RNA helicase gene, which we named HelTc. Southern blot analysis indicated that HelTc is a single-copy gene. Pulsed-field gel electrophoresis separation of chromosomes of several isolates of T. cruzi showed that this gene was localized in one or two chromosomal bands.

Amino Acid Motifs↗
PubMedDate not supplied

[Clinical application of free microvascular flaps in reconstructive surgery of the oral cavity].

We present the results of reconstructive surgery after different surgical resections in the oral cavity. Reconstruction of the defects was made using free microvascularized flaps. We used a free radial fasciocutaneous or osteocutaneous flap in every case, with a 100% of viability and a low complication rate. This technique is widely versatile in the reconstruction of different oral defects, offering an adequate replacement of oral mucosa.

Aged↗
PubMedDate not supplied

[Distortion of otoacoustic emission].

We present a review of the current literature and our experience with distortion product otoacoustic emissions. They represent a new tool for the clinical study of deafness as shown and of the basic functional status of the cochlea.

Acoustic Impedance Tests↗
PubMedDate not supplied

[Cochlear implants in post-lingual persons: results during the first five years of the clinical course].

Abundant literature is available on the results of cochlear implants in postlingual persons. Nevertheless, there are few long-term studies with a follow-up of more than 1 year. We present the outcomes of 37 postlingual patients with a 5-year follow-up period. We examined the modifications that occurred with changes in coding strategy (MPEAK-SPEAK). After activation, the coding strategy was SPEAK in 10 patients. MPEAK in 20: 7 other SPEAK had changed from MPEAK. Significant improvement (p < 0.01) was observed in all the tests in the first 6 months. Subsequent assessments revealed a constant improvement in all tests. The results were statistically significant (p < 0.05) for vowels, consonants and bisyllables. Performance with the SPEAK strategy was better than with MPEAK. These results were statistically significant for consonants (p < 0.05), monosyllables (p < 0.05) and bisyllables (p < 0.01). We concluded that the results of postlingual patients after cochlear implantation showed clear benefits of these devices in profound bilateral deafness, better results with the SPEAK coding strategy than with MPEAK and constant improvement in results, even after the first year of surgery.

Adolescent↗