Basal bodies exhibit polarized positioning in zebrafish cone photoreceptors

The asymmetric positioning of basal bodies, and therefore cilia, is often critical for proper cilia function. This planar polarity is critical for motile cilia function but has not been extensively investigated for nonmotile cilia or for sensory cilia such as vertebrate photoreceptors. Zebrafish photoreceptors form an organized mosaic ideal for investigating cilia positioning. We report that, in the adult retina, the basal bodies of red‐, green‐, and blue‐sensitive cone photoreceptors localized asymmetrically on the cell edge nearest the optic nerve. In contrast, no patterning was seen in the basal bodies of ultraviolet‐sensitive cones or in rod photoreceptors. The asymmetric localization of basal bodies was consistent in all regions of the adult retina. Basal body patterning was unaffected in the cones of the XOPS‐mCFP transgenic line, which lacks rod photoreceptors. Finally, the adult pattern was not seen in 7‐days‐postfertilization (dpf) larvae; basal bodies were randomly distributed in all the photoreceptor subtypes. These results establish the asymmetrical localization of basal bodies in red‐, green‐, and blue‐sensitive cones in adult zebrafish retinas but not in larvae. This pattern suggests an active cellular mechanism regulated the positioning of basal bodies after the transition to the adult mosaic and that rods do not seem to be necessary for the patterning of cone basal bodies. J. Comp. Neurol. 521:1803–1816, 2013. © 2012 Wiley Periodicals, Inc.     

Primary Immunodeficiency Diseases in Latin America: The Second Report of the LAGID Registry

This is the second report on the continuing efforts of LAGID to increase the recognition and registration of patients with primary immunodeficiency diseases in 12 Latin American countries: Argentina, Brazil, Chile, Colombia, Costa Rica, Honduras, Mexico, Panama, Paraguay, Peru, Uruguay, and Venezuela. This report reveals that from a total of 3321 patients registered, the most common form of primary immunodeficiency disease was predominantly antibody deficiency (53.2%) with IgA deficiency reported as the most frequent phenotype. This category was followed by 22.6% other well-defined ID syndromes, 9.5% combined T- and B-cell inmunodeficiency, 8.6% phagocytic disorders, 3.3% diseases of immune dysregulation, and 2.8% complement deficiencies. All countries that participated in the first publication in 1998 reported an increase in registered primary immunodeficiency cases, ranging between 10 and 80%. A comparison of the estimated minimal incidence of X-linked agammaglobulinemia, chronic granulomatous disease, and severe combined immunodeficiency between the first report and the present one shows an increase in the reporting of these diseases in all countries. In this report, the estimated minimal incidence of chronic granulomatous disease was between 0.72 and 1.26 cases per 100,000 births in Argentina, Chile, Costa Rica, and Uruguay and the incidence of severe combined immunodeficiency was 1.28 and 3.79 per 100,000 births in Chile and Costa Rica, respectively. However, these diseases are underreported in other participating countries. In addition to a better diagnosis of primary immunodeficiency diseases, more work on improving the registration of patients by each participating country and by countries that have not yet joined LAGID is still needed. Latin American Group for Primary Immunodeficiency Diseases     

Fracture healing following high energy tibial trauma: Ilizarov versus Taylor Spatial Frame

Introduction

The optimal treatment of high energy tibial fractures remains controversial and a challenging orthopaedic problem. The role of external fixators for all these tibial fractures has been shown to be crucial.

Methods

A five-year consecutive series was reviewed retrospectively, identifying two treatment groups: Ilizarov and Taylor Spatial Frame (TSF; Smith & Nephew, Memphis, TN, US). Fracture healing time was the primary outcome measure.

Results

A total of 112 patients (85 Ilizarov, 37 TSF) were identified for the review with a mean age of 45 years. This was higher in women (57 years) than in men (41 years). There was no significant difference between frame types (p=0.83). The median healing time was 163 days in both groups. There was no significant difference in healing time between smokers and non-smokers (180 vs 165 days respectively, p=0.07), open or closed fractures (p=0.13) or age and healing time (Spearman''s r=0.12, p=0.18). There was no incidence of non-union or re-fracture following frame removal in either group.

Conclusions

Despite the assumption of the rigid construct of the TSF, the median time to union was similar to that of the Ilizarov frame and the TSF therefore can play a significant role in complex tibial fractures.