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Biomedical subjects

S Ramirez

Publications and source records attributed to S Ramirez.

10 recordsLinked to original sources
PubMed1992

Neurorehabilitation following right thalamic infarct: effects of cognitive retraining on functional performance.

We treated the cognitive impairments of a 69-year-old male, that persisted 7 months after an infarction in the distribution of the right posterior cerebral artery. The infarct produced a 20% reduction in right cerebral blood flow, established by positron emission tomography (PET). Neuropsychological status was characterized by marked hemivisuospatial inattention, visuoperceptual and perceptuomotor dysfunction, and impaired visual memory. A multiple-baselines across behaviors design was utilized to assess effects of specific interventions on targeted cognitive functions. We found significant improvement in attention to left hemispace in response to directed interventions. Considerable gains were also realized in perceptuomotor abilities, mobility, and activities of daily living. Results indicated process-specific effects of strategic cognitive interventions, initiated 7 months postonset.

Aged↗
PubMed1991

Enhancer element at the 3'-flanking region controls transcriptional response to hypoxia in the human erythropoietin gene.

Erythropoietin gene expression is greatly stimulated under conditions of hypoxia. The activation of the erythropoietin gene appears regulated primarily at the level of gene transcription. To study cis-acting elements involved in the response to hypoxia a mini-gene was constructed by an internal deletion from exon II to V of the human erythropoietin gene and used in transient transfection assays in the erythropoietin producing Hep 3B cell line. It was initially found that hypoxia responsiveness was present in an erythropoietin fragment containing 400 base pairs (bp) of 5'-flanking and 600 bp of 3'-flanking regions. Deletion analysis showed no significant effect on the response to hypoxia when highly conserved regions of 5'-flanking sequence, exon and intron I, and exon V were removed from the mini-gene construct. However, removal of a fragment containing the 3' end of the gene and 3'-flanking sequences completely eliminated hypoxia responsiveness. Reinsertion of the above fragment upstream of the 5' end of the mini-gene restored the response to hypoxia. Further analysis using hybrid erythropoietin-chloramphenicol-acetyltransferase constructs allowed the localization of enhancer-like element(s) in the 3'-flanking region, approximately 120 bp downstream of the polyadenylation site of the human erythropoietin gene. Activation by these sequences were position- and orientation-independent and stimulated 15-fold transcription of the erythropoietin gene in response to hypoxia.

Cells, Cultured↗
PubMed1990

One-movement insertion of the superior loop into the bag.

An efficient, simple technique for one-movement insertion of the superior intraocular lens loop into the capsular bag is described. This bimanual technique avoids undue stress on the capsular bag and zonules, may be used with all extracapsular techniques, and is suitable for almost all flexible loop intraocular lenses designed for in-the-bag implantation.

Humans↗
PubMed1975

The 12p trisomy syndrome.

Trisomy for the short arm of chromosome number 12 was diagnosed (by a G-banding method) in a girl with multiple congenital defects. Her mother and two sisters showed a balanced translocation 46,XX,rcp(12;21)(p11;p11), so, the affected girl was the result of a maternal adjacen t-1 meiotic segregation with a karyotype 46,XX,der21,rcp(12;12)(p11;q11)mat. Another sister decreased at 3 yr of age showed similar phenotypical features and was considered also affected although no karyotype studies were performed. Both affected cases were compared with a previous one and the concordant characteristics allowed the individualization of the following syndrome: severe mental retardation, peculiar flat facies with prominent checks, epicanthic folds, broad and irregular implantation of the eyebrows, broad and flat nasal bridge with short and narrow nose, anteverted nostrils and large philtrum, broad and prominent lower lip, low set ears with folded helix, prominent anthelix and deep concha, "spade" shape fingers (sharp-pointed distal phalanges) with shortness of the fifth, bilateral genu valgum, slightly increased space between first and second toes, secral dimple, generalized hypotonia and hyporeflexia of knees and ankles, nistagmus, retarded and dysrythmic bone age, simian creases or equivalent and distal axial triradii.

Abnormalities, Multiple↗
PubMedDate not supplied

[Quantitative analysis of corneal excisions using argon fluoride excimer laser (193 nanometers)].

Excimer lasers represent a new and distinctive class of laser-tissue interaction termed photoablation. They can ablate materials with a high degree of precision and minimal damage to surrounding structures. The argon Fluoride excimer laser, which offers the possibility of non-contact corneal cutting, has a potential for clinical application of keratorefractive surgery. Since each pulse of excimer laser etches some amounts of tissue from the cornea, the repetitive pulses focused to a narrow line can create linear excisions. In this study, a quantitative analysis of both depth and width of corneal excisions was made on cadaver eyes at a given fluence (600 mj/cm2) and a constant repetitive rate (20Hz). The amount of ablation per pulse was not constant and the excisional depth did not show a linear correlation with pulse numbers. Both the depth and width of transversal excisions were more homogenous than those of radial excisions along the entire length of ablation.

Cornea↗