This paper reports the structure-dependent molecular orientation behavior of sericin, an adhesive silk protein secreted by silkworm, Bombyx mori. Although application of sericin as a biomaterial is anticipated because of its unique characteristics, sericin's physicochemical properties remain unclear, mainly because of its vulnerability to heat or alkaline treatment during separation from fibroin threads. This study employed intact sericin obtained from fibroin-deficient mutant silkworm to investigate the relationship between molecular orientation and the secondary structure of sericin. Sericin films were artificially stretched after moistening with aqueous ethanol of various concentrations. The resulting molecular orientation was analyzed using polarized infrared spectroscopy. These analyses indicated that formation of aggregated strands among extended sericin chains induced by ethanol treatment is the key to generating molecular orientation. Strong intermolecular hydrogen bonds are inferred to allow aggregated strands' stretching-force transmission, thereby causing molecular orientation.

Ants are eusocial insects that are found in most regions of the world. Within its caste, worker ants are responsible for various tasks that are required for colony maintenance. In their chemical communication, α-helical carrier proteins, odorant-binding proteins, and chemosensory proteins, which accumulate in the sensillum lymph in the antennae, play essential roles in transferring hydrophobic semiochemicals to chemosensory receptors. It has been hypothesized that semiochemicals are recognized by α-helical carrier proteins. The number of these proteins, however, is not sufficient to interact with a large number of semiochemicals estimated from chemosensory receptor genes. Here we shed light on this conundrum by identifying a Niemann–Pick type C2 (NPC2) protein from the antenna of the worker Japanese carpenter ant, Camponotus japonicus (CjapNPC2). CjapNPC2 accumulated in the sensillum cavity in the basiconic sensillum. The ligand-binding pocket of CjapNPC2 was composed of a flexible β-structure that allowed it to bind to a wide range of potential semiochemicals. Some of the semiochemicals elicited electrophysiolgical responses in the worker antenna. In vertebrates, NPC2 acts as an essential carrier protein for cholesterol from late endosomes and lysosomes to other cellular organelles. However, the ants have evolved an NPC2 with a malleable ligand-binding pocket as a moderately selective carrier protein in the sensillum cavity of the basiconic sensillum. CjapNPC2 might be able to deliver various hydrophobic semiochemicals to chemosensory receptor neurons and plays crucial roles in chemical communication required to perform the worker ant tasks.

ATF1, CREB1, and CREM constitute the CREB family of transcription factors. The genes encoding these factors are involved in gene fusion events in human tumors. EWSR1-ATF1 and EWSR1-CREB1 are the 2 most characterized fusions, whereas EWSR1-CREM has been less studied. To better understand the phenotypic spectrum of mesenchymal tumors associated with the EWSR1-CREM fusion, we investigated archival cases using fluorescence in situ hybridization and/or RNA sequencing. Among 33 clear cell sarcomas of soft tissue tested, we found 1 specimen, a hand tumor bearing the rearrangements of EWSR1 and CREM, with classic histology and immunophenotype. None of 6 clear cell sarcoma-like tumors of the gastrointestinal tract tested harbored the EWSR1-CREM fusion. Among 11 angiomatoid fibrous histiocytomas, we found that 3 tumors of myxoid variant harbored the rearrangements of EWSR1 and CREM. All 3 tumors occurred in middle-aged men and involved the distal extremities (N=2) and the lung (N=1). Prominent lymphoid cuff, fibrous pseudocapsule, and amianthoid fiber were present in 3, 2, and 2 tumors, respectively, whereas none showed pseudoangiomatoid spaces. All 3 tumors were immunohistochemically positive for epithelial membrane antigen and desmin. These cases suggested a closer relationship between angiomatoid fibrous histiocytoma and a recently proposed novel group of myxoid tumors with CREB family fusions. Our cohort also included 2 unclassifiable sarcomas positive for EWSR1-CREM. One of these was an aggressive pediatric tumor of the abdominal cavity characterized by proliferation of swirling spindle cells immunopositive for cytokeratin and CD34. The other tumor derived from the chest wall of an adult and exhibited a MUC4-positive sclerosing epithelioid fibrosarcoma-like histology. Our study demonstrates that a wider phenotypic spectrum is associated with the EWSR1-CREM fusion than previously reported.

The structure and stability of hydrogen bonds in alpha-chitin were investigated by (13)C solid-state NMR measurements at different temperatures. Splitting of the carbonyl carbon signal for alpha-chitin was interpreted as two types of hydrogen bonding; the peaks at 173.5 and 175.8 ppm were assigned, respectively, to a carbonyl carbon hydrogen bonded exclusively to the NH group and a carbonyl carbon hydrogen-bonded to both NH and C(6)-OH groups. Approximately 60% of carbonyl groups exclusively contributed to the intermolecular hydrogen bonding and ca. 40% of them to the combination of intermolecular and intramolecular hydrogen bonding. Internal rotation around the C(5)-C(6) bond was detected at 55 degrees C.

ObjectiveThe authors determined the effect of postoperative mediastinal irradiation in preventing local and pleural recurrences of thymoma. Summary Background DataThe role of mediastinal irradiation after incomplete resection or biopsy of an invasive thymoma is well established. However, routine use of adjuvant mediastinal irradiation for patients with thymoma after complete resection remains controversial. MethodsDuring the 19-year period from 1973 to 1992, operations were performed on 89 patients with thymoma. Of these 89 patients, 80 patients who underwent gross complete tumor resection including adjacent tissues that appeared to be invaded by tumor were selected for this study. The effects of postoperative mediastinal irradiation on the recurrence rate of thymoma were analyzed according to histologic type, clinical stage, and whether adhesions to or invasion of the pleura or pericardium were present. ResultsRecurrence of thymoma was observed in 13 of 80 (16.3%)