Ultraviolet recall reaction after total body irradiation, etoposide, and methotrexate therapy.

Ultraviolet (UV) reactivation reactions are rare and can occur in areas of prior sunburn or UV light therapy after the administration of chemotherapy, antibiotics, and other medications. Reactions may occur within days, as described after methotrexate therapy, or may appear months later, as described with ampicillin. Such reactions have been variably termed UV recall, sunburn recall, photo recall, and photodermatitis reactivation, making classification difficult. We report a UV reactivation reaction in a patient with acute lymphocytic leukemia treated with total body irradiation, etoposide, and methotrexate. We propose the terms UV recall and UV enhancement be used in future reports to classify UV reactivation reactions in a scheme analogous to the terminology for cutaneous reactions after radiotherapy

Control of star formation by supersonic turbulence

Understanding the formation of stars in galaxies is central to much of modern astrophysics. For several decades it has been thought that stellar birth is primarily controlled by the interplay between gravity and magnetostatic support, modulated by ambipolar diffusion. Recently, however, both observational and numerical work has begun to suggest that support by supersonic turbulence rather than magnetic fields controls star formation. In this review we outline a new theory of star formation relying on the control by turbulence. We demonstrate that although supersonic turbulence can provide global support, it nevertheless produces density enhancements that allow local collapse. Inefficient, isolated star formation is a hallmark of turbulent support, while efficient, clustered star formation occurs in its absence. The consequences of this theory are then explored for both local star formation and galactic scale star formation. (ABSTRACT ABBREVIATED)Comment: Invited review for "Reviews of Modern Physics", 87 pages including 28 figures, in pres

Article Comparative Transcriptome Analyses Reveal Core Parasitism Genes and Suggest Gene Duplication and Repurposing as Sources of Structural Novelty

Abstract The origin of novel traits is recognized as an important process underlying many major evolutionary radiations. We studied the genetic basis for the evolution of haustoria, the novel feeding organs of parasitic flowering plants, using comparative transcriptome sequencing in three species of Orobanchaceae. Around 180 genes are upregulated during haustorial development following host attachment in at least two species, and these are enriched in proteases, cell wall modifying enzymes, and extracellular secretion proteins. Additionally, about 100 shared genes are upregulated in response to haustorium inducing factors prior to host attachment. Collectively, we refer to these newly identified genes as putative "parasitism genes." Most of these parasitism genes are derived from gene duplications in a common ancestor of Orobanchaceae and Mimulus guttatus, a related nonparasitic plant. Additionally, the signature of relaxed purifying selection and/or adaptive evolution at specific sites was detected in many haustorial genes, and may play an important role in parasite evolution. Comparative analysis of gene expression patterns in parasitic and nonparasitic angiosperms suggests that parasitism genes are derived primarily from root and floral tissues, but with some genes co-opted from other tissues. Gene duplication, often taking place in a nonparasitic ancestor of Orobanchaceae, followed by regulatory neofunctionalization, was an important process in the origin of parasitic haustoria

Plaque-like myofibroblastic tumor of infancy.

Fibrohistiocytic neoplasms are relatively uncommon in infancy and childhood. We report an unusual spindle cell tumor occurring in two infants within the first 3 months of life. These tumors histologically resembled dermatofibromas, but the young age of onset, large size, and plaque-like morphology were distinctly different from those of dermatofibromas. The features of these neoplasms are discussed and the differential of other spindle cell tumors of infancy is reviewed

Tectonic Activity and Plate Boundaries along the Northern Flank of the Fiji Platform

Recent volcanic activity along the northern flank of the Fiji Platform, revealed for the first time from new GLORIA imagery, suggests that the loci of interplate motion in this region have migrated rapidly since the switch from Vitiaz to New Hebridean subduction at 5–8 Ma. At present the plate boundaries along the northern flank of the Fiji Platform consist of two major strike-slip faults of opposing sense: the sinistral Fiji Transform Fault along the northwest flank of the platform, and at least one (or possibly two) zones of dextral strike slip (including Peggy Ridge) along the northeast flank. The tectonic relation-ships of these two fault systems lies north of Fiji and is not determined

Gene Expression Signature as an Ancillary Method in the Diagnosis of Desmoplastic Melanoma

Desmoplastic melanoma (DM) is a rare fibrosing variant of melanoma that can be difficult to diagnose. One of the diagnostic challenges is its distinction from a melanocytic nevus with desmoplasia. Here we investigate the use of a 23-gene signature, which has previously been shown to distinguish benign from malignant melanocytic neoplasms. We assessed 50 cases with a differential diagnostic consideration of DM that underwent gene expression testing. Hematoxylin and eosin-stained sections were reviewed, and the final cohort included 20 DMs, 5 nondesmoplastic melanomas, and 27 desmoplastic melanocytic nevi. Of the 20 DMs, the gene expression score was positive ( likely malignant ) in 15 tumors, indeterminate in 1, and negative ( likely benign ) in 4. None of the desmoplastic melanocytic nevi were positive. The gene expression score was negative in 24 of the melanocytic nevi and indeterminate in the remaining 3. Nine DMs were also analyzed cytogenetically by single-nucleotide polymorphism (SNP) array. The SNP array revealed chromosomal copy number aberrations consistent with melanoma in 7 DMs and failed to show any aberrations in 2. The results of SNP array analysis and gene expression testing were discordant in 4 cases. Our results document limitations in the sensitivity of both the gene expression signature and SNP array for the detection of DM. Nonetheless, our findings suggest a potential role of the gene expression signature as ancillary supportive evidence for the distinction of DM from desmoplastic nevus because positive scores were only seen in melanomas

The Western Fiji Transform Fault and its role in the dismemberment of the Fiji Platform

The Fiji Transform Fault (FTF) is a sinistral transform fault trending nearly E-W from the central North Fiji Basin triple junction at 17°S, 174°E to the northern Lau Basin and is characterized by very high bathymetric relief and dispersed seismicity. SeaMARC II and GLORIA sidescan imagery reveal the structural fabric along the fault trace. From the triple junction to 176°E, the fault location is uncertain but lies within an area having northeast and southeast trending structures. It is believed that a right step in the fault trace has produced a component of compression. From 176°E to 179°E, the fault is clearly delineated next to the Fiji Platform and within two left step offsets are short spreading segments. It is hypothesized that periodic propagation of these short segments into the Fiji Platform has accompanied changes in the location of the fault and in so doing has broken off parts of the Fiji Platform

Ultraviolet recall reaction after total body irradiation, etoposide, and methotrexate therapy.

Ultraviolet (UV) reactivation reactions are rare and can occur in areas of prior sunburn or UV light therapy after the administration of chemotherapy, antibiotics, and other medications. Reactions may occur within days, as described after methotrexate therapy, or may appear months later, as described with ampicillin. Such reactions have been variably termed UV recall, sunburn recall, photo recall, and photodermatitis reactivation, making classification difficult. We report a UV reactivation reaction in a patient with acute lymphocytic leukemia treated with total body irradiation, etoposide, and methotrexate. We propose the terms UV recall and UV enhancement be used in future reports to classify UV reactivation reactions in a scheme analogous to the terminology for cutaneous reactions after radiotherapy

Methotrexate-associated lymphoproliferative disorder in a patient with rheumatoid arthritis presenting in the skin.

A 91-year-old woman who had been taking methotrexate for approximately 5 years for rheumatoid arthritis developed papules and nodules on her face that enlarged during 6 months. A series of biopsy specimens demonstrated a lymphoplasmacytic infiltrate with increasingly atypical histopathologic features that resembled diffuse large B-cell lymphoma. Epstein-Barr virus was not identified. Withdrawal of methotrexate resulted in complete resolution of all lesions within 8 weeks. This case illustrates the rare occurrence of methotrexate-associated lymphoproliferative disorder with primary presentation in the skin and documents clinical and histopathologic progression from early changes to fully developed lesions