CD34‐positive superficial myxofibrosarcoma: a potential diagnostic pitfall

Background Myxofibrosarcoma (MFS) arises most commonly in the proximal extremities of the elderly, where it may involve subcutaneous and dermal tissues and masquerade as benign entities in limited biopsy samples. We encountered such a case, in which positivity for CD34 and morphologic features were initially wrongly interpreted as a ‘low‐fat/fat‐free’ spindle cell/pleomorphic lipoma. Case series have not assessed prevalence of CD34 reactivity among cutaneous examples of MFS. Methods We performed a systematic review of our institution's experience, selecting from among unequivocal MFS resection specimens those superficial cases in which a limited biopsy sample might prove difficult to interpret. These cases were immunostained for CD34 and tabulated for clinicopathologic characteristics. Results After review of all MFS diagnoses over 5 years (n = 56), we identified a study group of superficial MFS for comparison to the index case (total n = 8). Of these, the index and three additional cases (4 of 8, 50%; 2 low, 2 high grade) demonstrated positive staining for CD34 , with diffuse staining of spindled cells including cellular processes. Four additional cases showed no or equivocal/rare staining. Conclusions CD34 positivity should be recognized as prevalent among such cases and should not be inappropriately construed as inveighing against a diagnosis of MFS in favor of benign entities.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98187/1/cup12158.pd

Epithelial Cell Wedging and Neural Trough Formation Are Induced Planarly inXenopus,without Persistent Vertical Interactions with Mesoderm

AbstractIn this study we investigate the induction of the cell behaviors underlying neurulation in the frog,Xenopus laevis.Although planar signals from the organizer can induce convergent extension movements of the posterior neural tissue in explants, the remaining morphogenic processes of neurulation do not appear to occur in absence of vertical interactions with the organizer (R. Kelleret al.,1992,Dev. Dyn.193, 218–234). These processes include: (1) cell elongation perpendicular to the plane of the epithelium, forming the neural plate; (2) cell wedging, which rolls the neural plate into a trough; (3) intercalation of two layers of neural plate cells to form one layer; and (4) fusion of the neural folds. To allow planar signaling between all the inducing tissues of the involuting marginal zone and the responding prospective ectoderm, we have designed a “giant sandwich” explant. In these explants, cell elongation and wedging are induced in the superficial neural layer by planar signals without persistent vertical interactions with underlying, involuted mesoderm. A neural trough forms, and neural folds form and approach one another. However, the neural folds do not fuse with one another, and the deep cells of these explants do not undergo their normal behaviors of elongation, wedging, and intercalation between the superficial neural cells, even when planar signals are supplemented with vertical signaling until the late midgastrula (stage 11.5). Vertical interactions with mesoderm during and beyond the late gastrula stage were required for expression of these deep cell behaviors and for neural fold fusion. These explants offer a way to regulate deep and superficial cell behaviors and thus make possible the analysis of the relative roles of these behaviors in closing the neural tube

2004) Decreased apoptosis in the forebrain of adult male medaka (Oryzias latipes) after aqueous exposure to ethinylestradiol

Abstract Endocrine disrupting compounds (EDCs), especially those that are estrogenic, are an issue of growing concern because they may ultimately adversely affect wildlife survival. 17-h-Estradiol and its synthetic counterpart, 17-a-ethinylestradiol, two common EDCs, are associated with intersex conditions and impaired male reproductive behavior in fish. Male and female Japanese medaka (Oryzias latipes) were exposed to 10 ng/l ethinylestradiol for 6 months. Using terminal dideoxynucleotidyl-mediated dUTP nick end-labeling (TUNEL) to quantitate cell death, we found that ethinylestradiol-exposed males had significantly fewer apoptotic cells in the forebrain compared to untreated males and exposed females. Our results show that the effects of ethinylestradiol exposure are highly variable among individuals of the same species and even within tissues of the same individual. Thus, when examining the effects of EDCs on natural populations, data from a variety of tissues should be examined and the interpretation of any effects should include consideration of tissue-specific processes

Twelve tips for developing, implementing, and sustaining medical education fellowship programs: Building on new trends and solid foundations

Medical education fellowship programs (MEFPs) are a form of faculty development contributing to an organization\u27s educational mission and participants\u27 career development. Building an MEFP requires a systematic design, implementation, and evaluation approach which aligns institutional and individual faculty goals. Implementing an MEFP requires a team of committed individuals who provide expertise, guidance, and mentoring. Qualified MEFP directors should utilize instructional methods that promote individual and institutional short and long term growth. Directors must balance the use of traditional design, implementation, and evaluation methodologies with advancing trends that may support or threaten the acceptability and sustainability of the program. Drawing on the expertise of 28 MEFP directors, we provide twelve tips as a guide to those implementing, sustaining, and/or growing a successful MEFP whose value is demonstrated by its impacts on participants, learners, patients, teaching faculty, institutions, the greater medical education community, and the population\u27s health