Live Cell Labeling of Glial Progenitor Cells Using Targeted Quantum Dots

This study describes the development of targeted quantum dots (T-QDs) as biomarkers for the labeling of glial progenitor cells (GPCs) that over express platelet derived growth factor (PDGF) and its receptor PDGFR (GPC^PDGF). PDGFR plays a critical role in glioma development and growth, and is also known to affect multiple biological processes such as cell migration and embryonic development. T-QDs were developed using streptavidin-conjugated quantum dots (S-QDs) with biotinylated antibodies and utilized to label the intracellular and extracellular domains of live, cultured GPC^PDGF cells via lipofection with cationic liposomes. Confocal studies illustrate successful intracellular and extracellular targeted labeling within live cells that does not appear to impact upstream PDGFR dynamics during real-time signaling events. Further, T-QDs were nontoxic to GPC^PDGF cells, and did not alter cell viability or proliferation over the course of 6 days. These results raise new applications for T-QDs as ultra sensitive agents for imaging and tracking of protein populations within live cells, which that will enable future mechanistic study of oncogenic signaling events in real-time.     

Autism Spectrum Disorders and Childhood-Onset Schizophrenia: Clinical and Biological Contributions to a Relation Revisited

ObjectiveTo highlight emerging evidence for clinical and biological links between autism/pervasive developmental disorder (PDD) and schizophrenia, with particular attention to childhood-onset schizophrenia (COS).MethodClinical, demographic, and brain developmental data from the National Institute of Mental Health (and other) COS studies and selected family, imaging, and genetic data from studies of autism, PDD, and schizophrenia were reviewed.ResultsIn the two large studies that have examined this systematically, COS is preceded by and comorbid with PDD in 30% to 50% of cases. Epidemiological and family studies find association between the disorders. Both disorders have evidence of accelerated trajectories of anatomic brain development at ages near disorder onset. A growing number of risk genes and/or rare small chromosomal variants (microdeletions or duplications) are shared by schizophrenia and autism.ConclusionsBiological risk does not closely follow DSM phenotypes, and core neurobiological processes are likely common for subsets of these two heterogeneous clinical groups. Long-term prospective follow-up of autistic populations and greater diagnostic distinction between schizophrenia spectrum and autism spectrum disorders in adult relatives are needed.     

Multidisciplinary approach to the persistent double distal tendon of the biceps brachii

Purpose

The aim of this study is to correlate the ultrasound (US) appearance of the persistent double or bifid distal tendon of the biceps brachii muscle with anatomical and histological data. This will provide a new model to study the pathological distal biceps brachii tendon (DBBT).

Methods

The DBBT of 20 cadaveric elbows were examined with linear array broadband US transducers (frequency band 14–6 MHz) using an anterior approach. Trypan blue dye was injected underneath the paratenon under US guidance in 16 specimens. After they were dissected, five of them were processed to obtain histological slices stained with hematoxylin–eosin and antiserum to protein S100.

Results

At US, the DBBT is a tendon in which the fascicles are organized in two different hyperechoic components separated by a hyperechoic septum related to the endotenon. The endotenon is lax, flexible, and makes folding and gliding of the two portions feasible. The DBBT is surrounded by a hyperechoic paratenon adjacent to the tendon surface, which is only differentiable by US when dye is interposed between such structures.

Conclusions

The connective septum of endotenon located between the two main components of the DBBT is responsible for the US image of two separate tendons and functionally enables it to work as two separate entities, thus allowing respective folding and gliding. The paratenon surrounding the lacertus fibrosus and the DBBT plays an important stabilization role, enabling them to change shape and arrangement during joint motion. It is also an important conduit for nerves and blood vessels.