Combined therapy of bilateral transcranial direct current stimulation and ocular occlusion improves visual function in adults with amblyopia, a randomized pilot study.

Background: Amblyopia is the interocular visual acuity difference of two lines or more with the best correction in both eyes. It is treated with ocular occlusion therapy, but its success depends on neuroplasticity, and thus is effective in children but not adults. Transcranial Direct Current Stimulation (tDCS) is suggested to increase neuroplasticity. Objective: To determine if combined intervention of bilateral tDCS and ocular occlusion improves visual function in adults with amblyopia. Methods: A double-blind randomized, controlled pilot trial was conducted in 10 volunteers with amblyopia. While applying ocular occlusion and performing a reading task, participants received bilateral tDCS (n = 5) or sham stimulation (n = 5), with the anodal tDCS electrode in the contralateral visual cortex and the cathodal in the ipsilateral visual cortex in relation to the amblyopic eye. Visual function (through visual acuity, stereopsis, and contrast sensitivity tests) and visual evoked potential (with checkerboard pattern stimuli presentation) were evaluated immediately after. Results: A total of 30 min after treatment with bilateral tDCS, visual acuity improved by 0.16 (± 0.025) LogMAR in the treatment group compared with no improvement (-0.02 ± 0.02) in five controls (p = 0.0079), along with a significant increase in the amplitude of visual evoked potentials of the amblyopic eye response (p = 0.0286). No significant changes were observed in stereopsis and contrast sensitivity. No volunteer reported any harm derived from the intervention. Conclusion: Our study is the first to combine anodal and cathodal tDCS for the treatment of amblyopia, showing transient improved visual acuity in amblyopic adults.

Experimental and theoretical 2p core-level spectra of size-selected gas-phase aluminum and silicon cluster cations: chemical shifts, geometric structure, and coordination-dependent screening.

We present 2p core-level spectra of size-selected aluminum and silicon cluster cations from soft X-ray photoionization efficiency curves and density functional theory. The experimental and theoretical results are in very good quantitative agreement and allow for geometric structure determination. New ground state geometries for Al12+, Si15+, Si16+, and Si19+ are proposed on this basis. The chemical shifts of the 2p electron binding energies reveal a substantial difference for aluminum and silicon clusters: while in aluminum the 2p electron binding energy decreases with increasing coordination number, no such correlation was observed for silicon. The 2p binding energy shifts in clusters of both elements differ strongly from those of the corresponding bulk matter. For aluminum clusters, the core-level shifts between outer shell atoms and the encapsulated atom are of opposite sign and one order of magnitude larger than the corresponding core-level shift between surface and bulk atoms in the solid. For silicon clusters, the core-level shifts are of the same order of magnitude in clusters and in bulk silicon but no obvious correlation of chemical shift and bond length, as present for reconstructed silicon surfaces, are observed.

Maximum spin polarization in chromium dimer cations as demonstrated by X-ray magnetic circular dichroism spectroscopy.

X-ray magnetic circular dichroism spectroscopy has been used to characterize the electronic structure and magnetic moment of Cr2 (+) . Our results indicate that the removal of a single electron from the 4sσg bonding orbital of Cr2 drastically changes the preferred coupling of the 3d electronic spins. While the neutral molecule has a zero-spin ground state with a very short bond length, the molecular cation exhibits a ferromagnetically coupled ground state with the highest possible spin of S=11/2, and almost twice the bond length of the neutral molecule. This spin configuration can be interpreted as a result of indirect exchange coupling between the 3d electrons of the two atoms that is mediated by the single 4s electron through a strong intraatomic 3d-4s exchange interaction. Our finding allows an estimate of the relative energies of two states that are often discussed as ground-state candidates, the ferromagnetically coupled (12) Σ and the low-spin (2) Σ state.

Anticipation in familial lattice corneal dystrophy type I with R124C mutation in the TGFBI (BIGH3) gene.

PURPOSE: To report the clinical, ophthalmic, and genetic characteristics for lattice corneal dystrophy type I (LCDI) in a Chilean family. METHODS: Six affected family members were examined clinically including visual acuity, color cornea photography, applanation tonography, and fundoscopy. Genomic DNA was extracted from peripheral leukocytes from six affected and three unaffected members of a family with lattice corneal dystrophy type I. Exon 4 of the transforming growth factor-induced gene (TGFBI) was screened for the most frequent mutation, R124C, in the proband by sequencing. We also designed a rapid polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method to analyze the same mutation, amplifying exon 4 and digesting with PstI restriction enzyme. Using this strategy, we analyzed the mutation in six affected and three healthy family members. RESULTS: Three generations of family members were positively diagnosed with lattice corneal dystrophy. Six participants demonstrated LCD1 in both eyes, most of whom were symmetric. Age at onset of symptoms was variable (3-42 years old). Moreover, in this family, the age of onset of the disease decreased in succeeding generations, which could be interpreted as anticipation. Visual acuity varied from 1.0 to 0.13. Two patients, ages 69 and 44 years old, demonstrated a degree of severity "Bad" according to best-corrected vision and corneal commitment. The exon 4 sequence of TGFBI of the proband exhibits the heterozygous single-nucleotide mutation, C417T, leading to amino acid substitution (R124C) in the encoded TGF-induced protein. Using PCR-RFLP, we confirmed the heterozygous mutation in six affected family members and excluded it in three healthy members. CONCLUSIONS: The R124C mutation in TGFBI cosegregated with LCD type I in the investigated family. This is the first report of a molecular analysis of LCD type I in Chilean patients. The early onset affected persons in the fourth generation raises the possibility of anticipation.

Guía clínica de refracción en el niño / Clinical guide: refraction in children

Es importante detectar y manejar un error refractivo que pueda afectar el desarrollo de la visión asi la educación en la infancia. Se han realizado estudios de prevalencia así como el desarrollo de un programa nacional en Chile, a través de JUNAEB, que permitieron desarrollar esta guía de orientación para el desarrollo de programas similares en otras áreas de Latinoamérica.

1t is important to detect and manage a refractive error that could affect visual development, as well education, in chilhood. Prevalence studies has been done, as well as the development of a national program in Chile, by means of JUNAEB. Those developments has helped us to design this orientation guide used for similar purposes in other areas of Latin America.

Identification of KIF21A mutations as a rare cause of congenital fibrosis of the extraocular muscles type 3 (CFEOM3).

PURPOSE: Three congenital fibrosis of the extraocular muscles phenotypes (CFEOM1-3) have been identified. Each represents a specific form of paralytic strabismus characterized by congenital restrictive ophthalmoplegia, often with accompanying ptosis. It has been demonstrated that CFEOM1 results from mutations in KIF21A and CFEOM2 from mutations in PHOX2A. This study was conducted to determine the incidence of KIF21A and PHOX2A mutations among individuals with the third CFEOM phenotype, CFEOM3. METHODS: All pedigrees and sporadic individuals with CFEOM3 in the authors' database were identified, whether the pedigrees were linked or consistent with linkage to the FEOM1, FEOM2, and/or FEOM3 loci was determined, and the appropriate pedigrees and the sporadic individuals were screened for mutations in KIF21A and PHOX2A. RESULTS: Twelve CFEOM3 pedigrees and 10 CFEOM3 sporadic individuals were identified in the database. The structures of eight of the pedigrees permitted the generation of meaningful linkage data. KIF21A was screened in 17 probands, and mutations were identified in two CFEOM3 pedigrees. One pedigree harbored a novel mutation (2841G-->A, M947I) and one harbored the most common and recurrent of the CFEOM1 mutations identified previously (2860C-->T, R954W). None of CFEOM3 pedigrees or sporadic individuals harbored mutations in PHOX2A. CONCLUSIONS: The results demonstrate that KIF21A mutations are a rare cause of CFEOM3 and that KIF21A mutations can be nonpenetrant. Although KIF21A is the first gene to be associated with CFEOM3, the results imply that mutations in the unidentified FEOM3 gene are the more common cause of this phenotype.

Heterozygous mutations of the kinesin KIF21A in congenital fibrosis of the extraocular muscles type 1 (CFEOM1).

Congenital fibrosis of the extraocular muscles type 1 (CFEOM1; OMIM #135700) is an autosomal dominant strabismus disorder associated with defects of the oculomotor nerve. We show that individuals with CFEOM1 harbor heterozygous missense mutations in a kinesin motor protein encoded by KIF21A. We identified six different mutations in 44 of 45 probands. The primary mutational hotspots are in the stalk domain, highlighting an important new role for KIF21A and its stalk in the formation of the oculomotor axis.

Estudio de tuberculosis urogenital: Servicio de Urología, Hospiral San Juan de Dios 1975-1989 / Genitourinary tuberculosis study: urologic service, Hospital San Juan de Dios 1975-1989

Se estudian 64 casos con tuberculosis urogenital tratados en el Hospital San Juan de Dios durante 1975-1989. Se excluyeron 42 casos del período por datos incompletos. Los principales síntomas de presentación fueron: urinarios (81%), hematuria (57%) y masa genital (53%). El cultivo de Koch en orina fue positivo en el 79%. Los hallazgos pielográficos más frecuentes fueron: alteración de cálices (50%) y exclusión o atrofia renal (40%). En el examen de orina se encontró piuria aséptica (87%) y hematuria macroscópica (81%). Esta presentación no discute el tratamiento

Evaluación del apoyo afectivo en estudiantes de medicina con la prueba de Apgar de Smilksteina / Assesment of effect support in students of medicine through Smilkstein's Apgar tests

La evaluación rápida del apoyo afectivo individual es necesaria y útil en la práctica médica. Esta se ha hecho, en adolescentes, aplicando el Apgar Familiar y el de las amistades de Smilkstein. El presente trabajo mide, con estos instrumentos, el apoyo familiar y de las amistades en estudiantes de medicina, quienes por su sistema de estudio se ven sometidos a una fuerte presión curricular. Ambos Apgar se aplicaron a 499 alumnos correspondientes al 90,7% del total de 550 de la División de Ciências Médicas Occidente de la Universidad de Chile. El 39,1% de ellos eran menores de 21 años (n = 195) y el 40% (n = 200) eran mujeres. Las encuestas se realizaron entre Octubre de 1986 y Mayo de 1987. El Apgar satisfactorio (8 puntos o más) se encontró en el 59,9% de los casos encuestados en AF y AA. El intermedio (4-7 puntos) fue 32,3% en el Apgar familiar y 35,5% en el Apgar de las amistades. El bajo (-4 puntos) fue 7,8% en Apgar familiar y 4,6% en Apgar de las amistades (Diferencia significativa). El Apgar familiar bajo fue 9,4% en hombres y 5,5% en mujeres. El Apgar familiar bajo fue más frecuente que el Apgar de amistades bajo en cinco de los siete cursos y dos cursos destacaron por tener más de 10% de Apgar familiar bajo. Las mujeres tuvieron frecuencia significativamente más alta de Apgar de amistades satisfactorio. En total de 499 estudiantes un 19,2% tuvo Apgar familiar inferior a 6 puntos; cifra significativamente menor que la encontrada en adolescentes del área Oriente de Santiago. Se post