Gonadogenesis and slow proliferation of germ cells in juveniles of cultured yellowfin tuna, Thunnus albacares.

To develop techniques for seedling production of yellowfin tuna, the behavior of primordial germ cells (PGCs) and gonadogenesis were examined at 1-30 days post hatching (dph) using morphometric analysis, histological examination, and in situ hybridization. Immediately after hatching, PGCs were located on the dorsal side of the posterior end of the rectum under the peritoneum of the larvae, and at 3 dph they came into contact with stromal cells. PGCs and stromal cells gradually moved forward from the anus prior to 5 dph. At 7-10 dph, germ cells were surrounded by stromal cells and the gonadal primordia were formed. In individuals collected at 12 dph, PGCs were detected by in situ hybridization using a vasa mRNA probe that is a germ-cell-specific detection marker. The proliferation of germ cells in the gonadal primordia began at 7-10 dph. We observed double the number of germ cells at 30 dph (22 ± 3.2 cells), compared to that at 1 dph (11 ± 2.1 cells). Therefore, based on our data and previous reports, the initial germ cell proliferation of yellowfin tuna is relatively slower than that of other fish species.

Stereoscopic three-dimensional visualization applied to multimodal brain images: clinical applications and a functional connectivity atlas.

Effective visualization is central to the exploration and comprehension of brain imaging data. While MRI data are acquired in three-dimensional space, the methods for visualizing such data have rarely taken advantage of three-dimensional stereoscopic technologies. We present here results of stereoscopic visualization of clinical data, as well as an atlas of whole-brain functional connectivity. In comparison with traditional 3D rendering techniques, we demonstrate the utility of stereoscopic visualizations to provide an intuitive description of the exact location and the relative sizes of various brain landmarks, structures and lesions. In the case of resting state fMRI, stereoscopic 3D visualization facilitated comprehension of the anatomical position of complex large-scale functional connectivity patterns. Overall, stereoscopic visualization improves the intuitive visual comprehension of image contents, and brings increased dimensionality to visualization of traditional MRI data, as well as patterns of functional connectivity.

Symptom prevalence of ADHD and ODD in a pediatric population in Argentina.

OBJECTIVE: To assess the prevalence of DSM III-R symptoms of attention deficit hyperactivity disorder (ADHD) and oppositional defiant disorder (ODD) in an outpatient pediatric population; to compare oppositional behavior and grade retention rates; and to establish local means and standard deviations (SD) for the ADHD rating scale. METHOD: 300 children (149m, 151f; 6 to12 yrs) were evaluated for ADHD and ODD symptoms with the DuPaul and an author-designed rating scale, respectively. Scores 1.5 SD above the mean were considered positive for each disorder. RESULTS: A total of 27 subjects (13m, 14f), 9%, had positive scores consistent with ADHD. These children had an oppositional behavior rate of 33.3% and a grade retention rate of 30.7%. Those who did not have positive scores for ADHD had a rate of 5.5% and 7.3%, respectively. The mean scores for the boys on the ADHD rating scale was 17.1 (SD = 8.6); the girls had a mean of 14.7 (SD = 7.3). CONCLUSION: The prevalence rates in our study are similar to those found in other countries.

Utilidad de la RM ultra-rápida en el diagnóstico de la patología fetal / Diagnostic value of ultrafast fetal MRI

Propósito: presentación de casos con patología fetal estudiados mediante secuencias ultrarrápidas de RM. Material y métodos: se estudiaron 12 pacientes (14 fetos) cursando el 2º y 3º trimestre de embarazo con US y RM obstétricas. Para la RM se implementaron secuencias ultrarrápidas (Half Fourier Single Shot Turbo SE, HASTE). No se implementó sedación materna ni fetal. Resultados: los hallazgos de los 12 casos con anomalías fetales fueron: quistes por duplicación intestinal (n=1), estenosis pieloureteral y displasia multiquística renal (n=1), atresia esofágica (n=1), síndrome acárdico-anencefálico (n=1), holoprosencefalia semilobar (n=1), hernia diafragmática congénita (n=1), malformación adenomatoidea quística (n=1), onfalocele asociado a escoliosis (n=1), gastrosquisis (n=1), estenosis duodenal (n=1), teratoma cervical (n=1) y atresia ureteral (n=1). Conclusión: las secuencias ultrarrápidas permiten es estudio por RM de pacientes cursando el 2º/3º trimestre del embarazo, sin requerimiento de sedación. Se utiliza como complemento de US para la confirmación de anomalías fetales. La información aportada permite la toma de decisiones terapéuticas adecuadas

Utilidad de la RM ultra-rápida en el diagnóstico de la patología fetal / Diagnostic value of ultrafast fetal MRI

Propósito: presentación de casos con patología fetal estudiados mediante secuencias ultrarrápidas de RM. Material y métodos: se estudiaron 12 pacientes (14 fetos) cursando el 2º y 3º trimestre de embarazo con US y RM obstétricas. Para la RM se implementaron secuencias ultrarrápidas (Half Fourier Single Shot Turbo SE, HASTE). No se implementó sedación materna ni fetal. Resultados: los hallazgos de los 12 casos con anomalías fetal