Cell transformation by Rous sarcoma virus results in a dramatic change of adhesion structures with the substratum. Adhesion plaques are replaced by dot-like attachment sites called podosomes. Podosomes are also found constitutively in motile nontransformed cells such as leukocytes, macrophages, and osteoclasts. They are represented by columnar arrays of actin which are perpendicular to the substratum and contain tubular invaginations of the plasma membrane. Given the similarity of these tubules to those generated by dynamin around a variety of membrane templates, we investigated whether dynamin is present at podosomes. Immunoreactivities for dynamin 2 and for the dynamin 2–binding protein endophilin 2 (SH3P8) were detected at podosomes of transformed cells and osteoclasts. Furthermore, GFP wild-type dynamin 2aa was targeted to podosomes. As shown by fluorescence recovery after photobleaching, GFP-dynamin 2aa and GFP-actin had a very rapid and similar turnover at podosomes. Expression of the GFP-dynamin 2aaG273D abolished podosomes while GFP-dynaminK44A was targeted to podosomes but delayed actin turnover. These data demonstrate a functional link between a member of the dynamin family and actin at attachment sites between cells and the substratum.

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Retinoblastoma is a rare and curable malignancy affecting the pediatric population. For advanced stage intraocular retinoblastoma, enucleation remains the primary treatment modality, although the use of laser photocoagulation, cryotherapy, radiotherapy and chemotherapy are frequently used, particularly in the setting of bilateral disease. Intravenous chemotherapy is the long-standing method of delivery, but local administration (subtenon, intravitreal or intra-arterial) is gaining in popularity because of the reduced side effects related to systemic administration. Of these newer methods, intra-arterial infusion has demonstrated technical feasibility, few procedural complications and robust tumor response. A case is described where a collateral supply to the affected ophthalmic artery was via the zygomatico-orbital branch of the ipsilateral superficial temporal artery. Melphalan infusion was performed via this pathway without incident.

The purpose of this qualitative investigation was to explore the learning of six in-service U.S. teachers who engaged in a cross-cultural learning experience during the summer of 2001. The teachers were enrolled in a graduate seminar conducted in English and entitled "Literacy Across Languages and Cultures." Cindy (the first author of this manuscript) was the course instructor. The primary emphasis of the course was exploring current conceptions of quality literacy instruction for children from diverse backgrounds in mainstream U. S. classrooms. One credit of the three-credit course was conducted on WebCT in the United States. Two credits of the course were conducted at the Universidid Nacional in Heredia, Costa Rica. The teachers who were enrolled in the course lived with Costa Rican families for the month that they were studying in Costa Rica. In this investigation we sought to explore what we learned about literacy instruction for students from diverse backgrounds from course readings, one another, and a cross-cultural experience in Costa Rica. Our experiences positioned us to reexamine our own cultural frames of reference and our thinking about instructing children in our classrooms whose cultural and linguistic backgrounds are different from ours.